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2023-2024 ICPC, NERC, Northern Eurasia Onsite (Unrated, Online Mirror, ICPC Rules, Teams Preferred)/K. Kim's Quest.cpp

@@ -0,0 +1,182 @@
+/* Problem URL: https://codeforces.com/problemset/problem/1912/K */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+const ll mod = 998244353;
+constexpr int MAXN = 2e5 + 10;
+ll fact[MAXN];
+ll inv[MAXN];
+ll invf[MAXN];
+
+ll comb(ll n, ll k) {
+    return fact[n] * invf[k] % mod * invf[n - k] % mod;
+}
+
+void pre()
+{
+    fact[0] = 1;
+    nrep(i, 1, MAXN) {
+        fact[i] = fact[i - 1] * i % mod;
+    }
+
+    inv[1] = 1;
+    nrep(i, 2, MAXN) {
+        inv[i] = (mod - mod / i) * inv[mod % i] % mod;
+    }
+
+    invf[0] = 1;
+    nrep(i, 1, MAXN) {
+        invf[i] = invf[i - 1] * inv[i] % mod;
+    }
+}
+
+#define TEST 0
+
+void solve()
+{
+    int n;
+    cin >> n;
+    vl a(n);
+    ll c = 0;
+    repv(i, a) {
+        cin >> i;
+        c += ~i & 1;
+    }
+
+    ll ans = 0;
+    nrep(i, 3, c + 1) {
+        (ans += comb(c, i)) %= mod;
+    }
+    int seq[] = {1, 0, 1};
+
+    vvvl memo(n, vvl(3, vl(2, -1)));
+    auto init = [&]() {
+        rep(i, n) {
+            rep(j, 3) {
+                rep(k, 2) {
+                    memo[i][j][k] = -1;
+                }
+            }
+        }
+    };
+
+    function<ll(int, int, int)> dp = [&](int i, int c, int val) {
+        if (i >= n) {
+            return 0LL;
+        }
+
+        ll &ans = memo[i][c][val];
+        if (ans != -1) {
+            return ans;
+        }
+
+        ans = 0;
+        if (seq[c] == (a[i] & 1)) {
+            (ans += dp(i + 1, (c + 1) % 3, val || (c == 2)) + (val || (c == 2))) %= mod;
+        }
+        (ans += dp(i + 1, c, val)) %= mod;
+        return ans;
+    };
+
+    (ans += dp(0, 0, 0)) %= mod;
+    seq[0] = 0;
+    seq[1] = 1;
+    init();
+    (ans += dp(0, 0, 0)) %= mod;
+    seq[0] = 1;
+    seq[2] = 0;
+    init();
+    (ans += dp(0, 0, 0)) %= mod;
+
+    cout << ans << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

8VC Venture Cup 2017 - Elimination Round/C. PolandBall and Forest.cpp

@@ -0,0 +1,121 @@
+/* Problem URL: https://codeforces.com/contest/755/problem/C */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 0
+
+void solve()
+{
+    int n;
+    cin >> n;
+    set<int> s;
+    int ans = 0;
+    rep(i, n) {
+        int a;
+        cin >> a;
+        if (a == i + 1) {
+            ans++;
+            continue;
+        }
+
+        s.insert(a);
+    }
+
+    cout << ans + (s.size() + 1) / 2 << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Alpha Round 20 (Codeforces format)/C. Dijkstra?.cpp

@@ -0,0 +1,153 @@
+/* Problem URL: https://codeforces.com/problemset/problem/20/C */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 0
+
+void solve()
+{
+    int n, m;
+    cin >> n >> m;
+
+    V<V<pair<int, ll>>> graph(n);
+
+    while (m--) {
+        int a, b, c;
+        cin >> a >> b >> c;
+        a--, b--;
+        graph[a].emplace_back(b, c);
+        graph[b].emplace_back(a, c);
+    }
+
+    vi p(n, -1);
+    vl dis(n, OO);
+    priority_queue<pair<ll, int>, V<pair<ll, int>>, greater<>> pq;
+    dis[0] = 0;
+    pq.emplace(0, 0);
+    while (!pq.empty()) {
+        auto [c, i] = pq.top();
+        pq.pop();
+
+        if (c > dis[i]) {
+            continue;
+        }
+
+        for (auto [j, w] : graph[i]) {
+            if (dis[j] > c + w) {
+                dis[j] = c + w;
+                p[j] = i;
+                pq.emplace(dis[j], j);
+            }
+        }
+    }
+
+    if (dis[n - 1] == OO) {
+        cout << "-1\n";
+        return;
+    }
+
+    vi ans;
+    int now = n - 1;
+    while (now != -1) {
+        ans.push_back(now + 1);
+        now = p[now];
+    }
+    reverse(all(ans));
+    cout << ans;
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 1071 (Div. 3)/D. Blackslex and Penguin Civilization.cpp

@@ -0,0 +1,121 @@
+/* Problem URL: https://codeforces.com/contest/2179/problem/D */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    cin >> n;
+
+    ll cur = (1 << n) - 1;
+    int lim = __builtin_popcount(cur);
+    int mod = 0;
+    rep(i, 1 << n) {
+        cout << cur + (mod << (__builtin_popcount(cur) + 1)) << ' ';
+        if (cur > 0 && __builtin_popcount(cur) + __builtin_popcount(mod) >= lim - 1) {
+            mod = 0;
+            cur ^= 1 << (31 - __builtin_clz(cur));
+        } else {
+            mod++;
+        }
+    }
+    cout << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 1074 (Div. 4)/E. The Robotic Rush.cpp

@@ -0,0 +1,160 @@
+/* Problem URL: https://codeforces.com/problemset/problem/2185/E */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n, m, q;
+    cin >> n >> m >> q;
+
+    vl a(n);
+    vl b(m);
+    cin >> a >> b;
+    sortv(b);
+
+    string c;
+    cin >> c;
+
+    V<pair<int, int>> mov(q + 1);
+    int now = 0;
+    nrep(i, 1, q + 1) {
+        char cur = c[i - 1];
+        mov[i] = mov[i - 1];
+        now += (cur == 'R') - (cur == 'L');
+        rmin(mov[i].first, now);
+        rmax(mov[i].second, now);
+    }
+
+    vi ans(q + 1);
+    ans[0] = n;
+    rep(i, n) {
+        int low = 0;
+        int high = q + 1;
+        while (low < high) {
+            int mid = (low + high) >> 1;
+
+            ll posl = a[i] + mov[mid].first;
+            ll posr = a[i] + mov[mid].second;
+
+            auto itr = lower_bound(all(b), posl);
+            auto itr2 = upper_bound(all(b), posr);
+
+            if (((itr == b.end()) || (*itr < posl || *itr > a[i])) && ((itr2 == b.begin()) || (*prev(itr2) > posr || *prev(itr2) < a[i]))) {
+                low = mid + 1;
+                continue;
+            }
+
+            high = mid;
+        }
+
+        if (low == q + 1) {
+            continue;
+        }
+
+        ans[low]--;
+    }
+
+    nrep(i, 1, q + 1) {
+        ans[i] += ans[i - 1];
+        cout << ans[i] << ' ';
+    }
+    cout << endl;
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 1077 (Div. 2)/A. Divisible Permutation.cpp

@@ -0,0 +1,119 @@
+/* Problem URL: https://codeforces.com/contest/2188/problem/A */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    cin >> n;
+
+    vi p(n);
+
+    for (int i = n - 1; i >= 0; i--) {
+        if ((n - i) & 1) {
+            p[i] = (n - i + 1) >> 1;
+            continue;
+        }
+
+        p[i] = n - ((n - i - 1) >> 1);
+    }
+    cout << p;
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 1077 (Div. 2)/B. Seats.cpp

@@ -0,0 +1,134 @@
+/* Problem URL: https://codeforces.com/problemset/problem/2188/B */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    cin >> n;
+    string a;
+    cin >> a;
+
+    int i = 0;
+    while (i < n && a[i] == '0') {
+        i++;
+    }
+
+    if (i == n) {
+        cout << (n + 2) / 3 << '\n';
+        return;
+    }
+
+    int ans = (i + 1) / 3;
+    int c = 0;
+    while (i < n) {
+        if (a[i] == '0') {
+            c++;
+        } else {
+            ans += c / 3;
+            c = 0;
+        }
+        i++;
+    }
+
+    ans += (c + 1) / 3;
+    cout << ans + count(all(a), '1') << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 1078 (Div. 2)/A. Lawn Mower.cpp

@@ -0,0 +1,108 @@
+/* Problem URL: https://codeforces.com/contest/2194/problem/A */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    ll h, w;
+    cin >> h >> w;
+    cout << h - h / w << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 1078 (Div. 2)/B. Offshores.cpp

@@ -0,0 +1,121 @@
+/* Problem URL: https://codeforces.com/contest/2194/problem/B */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    ll x, y;
+    cin >> n >> x >> y;
+
+    vl a(n);
+    ll sum = 0;
+    repv(i, a) {
+        cin >> i;
+        sum += i / x * y;
+    }
+
+    ll ans = 0;
+    repv(i, a) {
+        rmax(ans, i + sum - i / x * y);
+    }
+    cout << ans << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 1078 (Div. 2)/C. Secret message.cpp

@@ -0,0 +1,165 @@
+/* Problem URL: https://codeforces.com/contest/2194/problem/C */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n, k;
+    cin >> n >> k;
+
+    bitset<26> ev;
+    rep(i, 26) {
+        ev[i] = true;
+    }
+
+    V<string> a(k);
+    cin >> a;
+
+    vi divs;
+    vi tp;
+
+    for (int i = 1; i * i <= n; i++) {
+        if (n % i == 0) {
+            divs.push_back(i);
+            if (i * i != n) {
+                tp.push_back(n / i);
+            }
+        }
+    }
+    for (int i = tp.size() - 1; i >= 0; i--) {
+        divs.push_back(tp[i]);
+    }
+
+    string ans(n, ' ');
+
+    auto check = [&](int sz) {
+        rep(i, sz) {
+            bitset<26> val = ev;
+
+            for (int j = i; j < n; j += sz) {
+                bitset<26> cur;
+                rep(l, k) {
+                    cur[a[l][j] - 'a'] = true;
+                }
+                val &= cur;
+                if (val == 0) {
+                    return false;
+                }
+            }
+
+            char ch = 63 - __builtin_clzll(val.to_ullong()) + 'a';
+            for (int j = i; j < n; j += sz) {
+                ans[j] = ch;
+            }
+        }
+
+        return true;
+    };
+
+    repv(i, divs) {
+        if (check(i)) {
+            cout << ans << '\n';
+            return;
+        }
+    }
+
+    assert(false);
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 1078 (Div. 2)/D. Table Cut.cpp

@@ -0,0 +1,155 @@
+/* Problem URL: https://codeforces.com/contest/2194/problem/D */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n, m;
+    cin >> n >> m;
+
+    vvi a(n, vi(m));
+    ll c = 0;
+    repv(i, a) {
+        repv(j, i) {
+            cin >> j;
+            c += j == 1;
+        }
+    }
+
+    ll lim = c >> 1;
+    ll ans = lim * ((c + 1) >> 1);
+    ll cur = 0;
+
+    int i = n - 1;
+    int j = 0;
+
+    while (cur < lim) {
+        cur += a[i][j] == 1;
+        j++;
+        if (j >= m) {
+            j = 0;
+            i--;
+        }
+    }
+
+    string act;
+    rep(k, i) {
+        act.push_back('D');
+    }
+
+    rep(k, j) {
+        act.push_back('R');
+    }
+
+    act.push_back('D');
+    i++;
+
+    nrep(k, j, m) {
+        act.push_back('R');
+    }
+
+    nrep(k, i, n) {
+        act.push_back('D');
+    }
+
+    cout << ans << '\n';
+    cout << act << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 1092 (Unrated, Div. 2, Based on THUPC 2026 — Finals)/A. Course Wishes.cpp

@@ -0,0 +1,132 @@
+/* Problem URL: https://codeforces.com/contest/2216/problem/A */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n, k;
+    cin >> n >> k;
+
+    vi ans;
+
+    vi lim(k);
+    cin >> lim;
+
+    vi a(n);
+    cin >> a;
+    vi p(n);
+    iota(all(p), 0);
+    sort(all(p), [&](int i, int j){
+         return a[i] > a[j];
+         });
+
+    repv(i, p) {
+        nrep(j, a[i], k + 1) {
+            ans.push_back(i + 1);
+        }
+    }
+
+    cout << ans.size() << '\n';
+    repv(i, ans) {
+        cout << i << ' ';
+    }
+    cout << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 1092 (Unrated, Div. 2, Based on THUPC 2026 — Finals)/C. Interval Mod.cpp

@@ -0,0 +1,128 @@
+/* Problem URL: https://codeforces.com/contest/2216/problem/C */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n, k;
+    ll p, q;
+    cin >> n >> k >> p >> q;
+
+    vl a(n);
+    cin >> a;
+    vvl pref(3, vl(n + 1));
+    nrep(i, 1, n + 1) {
+        pref[0][i] = pref[0][i - 1] + a[i - 1] % p;
+        pref[1][i] = pref[1][i - 1] + a[i - 1] % q % p;
+        pref[2][i] = pref[2][i - 1] + min(a[i - 1] % p, a[i - 1] % q % p);
+    }
+
+    ll ans = OO;
+
+    nrep(i, k - 1, n) {
+        ll cur = min(pref[0][i + 1] - pref[0][i - k + 1], pref[1][i + 1] - pref[1][i - k + 1]);
+        ll bf = pref[2][i - k + 1] - pref[2][0];
+        ll af = pref[2][n] - pref[2][i + 1];
+        rmin(ans, cur + af + bf);
+    }
+    
+    cout << ans << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 1093 (Div. 2)/A. Blocked.cpp

@@ -0,0 +1,119 @@
+/* Problem URL: https://codeforces.com/contest/2220/problem/A */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    cin >> n;
+    vl a(n);
+    cin >> a;
+    sort(all(a), greater<>());
+
+    nrep(i, 1, n) {
+        if (a[i] == a[i - 1]) {
+            cout << "-1\n";
+            return;
+        }
+    }
+
+    cout << a;
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 1093 (Div. 2)/B. OIE Excursion.cpp

@@ -0,0 +1,127 @@
+/* Problem URL: https://codeforces.com/contest/2220/problem/B */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    ll m;
+    cin >> n >> m;
+
+    vl a(n);
+    cin >> a;
+
+    int c = 1;
+    nrep(i, 1, n) {
+        if (a[i] == a[i - 1]) {
+            c++;
+            if (c >= m) {
+                cout << "NO\n";
+                return;
+            }
+            continue;
+        }
+
+        c = 1;
+    }
+
+    cout << "YES\n";
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 1093 (Div. 2)/C. Grid L.cpp

@@ -0,0 +1,134 @@
+/* Problem URL: https://codeforces.com/contest/2220/problem/C */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    ll p, q;
+    cin >> p >> q;
+
+    auto test = [&](ll p, ll q) -> ll {
+        if (p < 0 || q < 0) {
+            return -1;
+        }
+
+        ll mi = min(p, q);
+        p -= mi;
+        q -= mi;
+
+        if (q || p % 3) {
+            return -1;
+        }
+
+        return mi + p / 3;
+    };
+
+    ll ans = -1;
+    rmax(ans, test(p - 4, q));
+    rmax(ans, test(p, q - 2));
+    rmax(ans, test(p - 2, q - 1));
+    if (ans == -1) {
+        cout << "-1\n";
+        return;
+    }
+
+    cout << "1 " << ans + 1 << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 1093 (Div. 2)/D1. Unique Values (Easy version).cpp

@@ -0,0 +1,164 @@
+/* Problem URL: https://codeforces.com/contest/2220/problem/D1 */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    cin >> n;
+
+    int sz = n * 2 + 1;
+
+    vi p(sz + 1, -1);
+    auto calc = [&](int mid) {
+        if (p[mid] != -1) {
+            return p[mid];
+        }
+        cout << "? " << mid;
+        nrep(i, 1, mid + 1) {
+            cout << ' ' << i;
+        }
+        cout << endl;
+        int s;
+        cin >> s;
+
+        cout << "? " << sz - mid;
+        nrep(i, mid + 1, sz + 1) {
+            cout << ' ' << i;
+        }
+        cout << endl;
+        int t;
+        cin >> t;
+
+        if (s > t) {
+            return p[mid] = 1;
+        }
+
+        if (t > s) {
+            return p[mid] = 2;
+        }
+
+        return p[mid] = ((mid - s) & 1) * 3;
+    };
+
+    auto ans = [&](int i, int j, int k) {
+        cout << "! " << i << ' ' << j << ' ' << k << endl;
+        return;
+    };
+
+    auto s = [&](int t) {
+        int low = 1;
+        int high = sz;
+        while (low < high) {
+            int mid = (low + high) >> 1;
+            if (calc(mid) >= t) {
+                high = mid;
+                continue;
+            }
+
+            low = mid + 1;
+        }
+
+        return low;
+    };
+
+    ans(s(1), s(2), s(3));
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 766 (Div. 2)/E. Not Escaping.cpp

@@ -0,0 +1,193 @@
+/* Problem URL: https://codeforces.com/contest/1627/problem/E */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n, m, k;
+    cin >> n >> m >> k;
+
+    vl x(n);
+    cin >> x;
+
+    vvi var(n);
+
+    V<tuple<int, int, int, int, int>> edges;
+    while (k--) {
+        int a, b, c, d, e;
+        cin >> a >> b >> c >> d >> e;
+        a--, b--, c--, d--;
+        edges.emplace_back(a, b, c, d, e);
+        var[a].push_back(b);
+        var[c].push_back(d);
+    }
+
+    var[0].push_back(0);
+
+    rep(i, n) {
+        sortv(var[i]);
+        var[i].erase(unique(all(var[i])), var[i].end());
+    }
+
+    vvl dis(n);
+    V<V<V<tuple<int, int, ll>>>> graph(n);
+    rep(i, n) {
+        graph[i].resize(var[i].size());
+        dis[i].assign(var[i].size(), OO);
+    }
+
+    for (auto [a, b, c, d, e] : edges) {
+        b = lower_bound(all(var[a]), b) - var[a].begin();
+        d = lower_bound(all(var[c]), d) - var[c].begin();
+
+        graph[a][b].emplace_back(c, d, e);
+    }
+
+    priority_queue<tuple<int, ll, int>, V<tuple<int, ll, int>>, greater<>> pq;
+    dis[0][0] = 0;
+    pq.emplace(0, 0, 0);
+
+    while (!pq.empty()) {
+        auto [i, c, j] = pq.top();
+        pq.pop();
+
+        if (c > dis[i][j]) {
+            continue;
+        }
+
+        for (auto [u, v, w] : graph[i][j]) {
+            if (dis[u][v] > c - w) {
+                dis[u][v] = c - w;
+                pq.emplace(u, c - w, v);
+            }
+        }
+
+        if (j > 0) {
+            ll dd = (var[i][j] - var[i][j - 1]) * x[i];
+            if (dis[i][j - 1] > c + dd) {
+                dis[i][j - 1] = c + dd;
+                pq.emplace(i, c + dd, j - 1);
+            }
+        }
+
+        if (j < var[i].size() - 1) {
+            ll dd = (var[i][j + 1] - var[i][j]) * x[i];
+            if (dis[i][j + 1] > c + dd) {
+                dis[i][j + 1] = c + dd;
+                pq.emplace(i, c + dd, j + 1);
+            }
+        }
+    }
+
+    ll ans = OO;
+    rep(i, dis[n - 1].size()) {
+        int v = var[n - 1][i];
+        ll dd = (m - v - 1) * x[n - 1] + dis[n - 1][i];
+        rmin(ans, dd);
+    }
+
+    if (ans == OO) {
+        cout << "NO ESCAPE\n";
+        return;
+    }
+
+    cout << ans << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 867 (Div. 3)/E. Making Anti-Palindromes.cpp

@@ -0,0 +1,167 @@
+/* Problem URL: https://codeforces.com/problemset/problem/1822/E */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    string a;
+    cin >> n >> a;
+
+    if (n & 1) {
+        cout << "-1\n";
+        return;
+    }
+
+    V<int> c(26);
+    repv(i, a) {
+        c[i - 'a']++;
+    }
+
+    rep(i, 26) {
+        if (c[i] > (n >> 1)) {
+            cout << "-1\n";
+            return;
+        }
+    }
+
+    multiset<int, greater<>> c2;
+    fill(all(c), 0);
+    rep(i, n >> 1) {
+        if (a[i] == a[n - i - 1]) {
+            c[a[i] - 'a']++;
+        }
+    }
+    rep(i, 26) {
+        if (c[i] > 0) {
+            c2.insert(c[i]);
+        }
+    }
+
+    int ans = 0;
+    while (c2.size() > 1) {
+        auto itr = c2.begin();
+        auto itr2 = next(itr);
+
+        int ca = *itr;
+        int cb = *itr2;
+        c2.erase(itr);
+        c2.erase(itr2);
+
+        ans++;
+        ca--;
+        cb--;
+
+        if (ca > 0) {
+            c2.insert(ca);
+        }
+
+        if (cb > 0) {
+            c2.insert(cb);
+        }
+    }
+
+    if (!c2.empty()) {
+        ans += *c2.begin();
+    }
+
+    cout << ans << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 891 (Div. 3)/F. Sum and Product.cpp

@@ -0,0 +1,141 @@
+/* Problem URL: https://codeforces.com/problemset/problem/1857/F */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    cin >> n;
+    map<ll, ll> c;
+    rep(i, n) {
+        ll a;
+        cin >> a;
+        c[a]++;
+    }
+
+    int q;
+    cin >> q;
+    while (q--) {
+        ll x, y;
+        cin >> x >> y;
+
+        ll d = x*x - 4 * y;
+        if (d < 0) {
+            cout << "0 ";
+            continue;
+        }
+
+        ll r1 = ceill((x - sqrtl(d)) / 2);
+        ll r2 = (x + sqrtl(d)) / 2;
+        if (r1 + r2 != x || r1 * r2 != y) {
+            cout << "0 ";
+            continue;
+        }
+
+        if (r1 == r2) {
+            cout << c[r1] * (c[r1] - 1) / 2 << ' ';
+            continue;
+        }
+
+        cout << c[r1] * c[r2] << ' ';
+    }
+    cout << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 913 (Div. 3)/F. Shift and Reverse.cpp

@@ -0,0 +1,159 @@
+/* Problem URL: https://codeforces.com/problemset/problem/1907/F */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    cin >> n;
+    map<ll, ll> c;
+    vl a(n);
+    repv(i, a) {
+        cin >> i;
+        c[i]++;
+    }
+
+    if (c.size() == 1) {
+        cout << "0\n";
+        return;
+    }
+
+    auto calcans = [&](vl &a, int val) {
+        ll b = prev(c.end())->first;
+
+        int k = 0;
+        while (a[k] != b) {
+            k++;
+        }
+
+        while (k < n && a[k] == b) {
+            k++;
+        }
+
+        int c = min(n - k, k + val * 2);
+        vl act;
+        nrep(i, k, n) {
+            act.push_back(a[i]);
+        }
+
+        rep(i, k) {
+            act.push_back(a[i]);
+        }
+
+        rep(i, n - 1) {
+            if (act[i] > act[i + 1]) {
+                return oo;
+            }
+        }
+
+        return c;
+    };
+
+    int cur = calcans(a, 1);
+    reverse(all(a));
+    rmin(cur, calcans(a, 0) + 1);
+
+    if (cur >= oo) {
+        cout << "-1\n";
+        return;
+    }
+    cout << cur << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 946 (Div. 3)/C. Beautiful Triple Pairs.cpp

@@ -0,0 +1,132 @@
+/* Problem URL: https://codeforces.com/problemset/problem/1974/C */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    cin >> n;
+    vi a(n);
+    cin >> a;
+
+    ll ans = 0;
+    map<pair<int, int>, ll> c1;
+    map<pair<int, int>, ll> c2;
+    map<pair<int, int>, ll> c3;
+    map<tuple<int, int, int>, ll> c4;
+    rep(i, n - 2) {
+        int a1 = a[i];
+        int a2 = a[i + 1];
+        int a3 = a[i + 2];
+
+        ans += c1[{a1, a2}];
+        ans += c2[{a1, a3}];
+        ans += c3[{a2, a3}];
+        ans -= c4[{a1, a2, a3}] * 3;
+
+        c1[{a1, a2}]++;
+        c2[{a1, a3}]++;
+        c3[{a2, a3}]++;
+        c4[{a1, a2, a3}]++;
+    }
+
+    cout << ans << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Codeforces Round 977 (Div. 2, based on COMPFEST 16 - Final Round)/C2. Adjust The Presentation (Hard Version).cpp

@@ -1,4 +1,4 @@
-/* Problem URL: https://codeforces.com/problemset/problem/2021/C2 */
+/* Problem URL: https://codeforces.com/contest/2021/problem/C2 */
 
 #include <bits/stdc++.h>
 #include <ext/pb_ds/assoc_container.hpp>
@@ -91,104 +91,75 @@ void solve()
     int n, m, q;
     cin >> n >> m >> q;
 
-    vi a(n);
-    cin >> a;
-
     vi var(n);
-    V<set<int>> ap(n);
+    V<set<int>> p(n);
     rep(i, n) {
-        var[a[i] - 1] = i;
-        ap[i].insert(oo);
+        int x;
+        cin >> x;
+        var[x - 1] = i;
+        p[i].insert(oo);
     }
 
     vi b(m);
     rep(i, m) {
         cin >> b[i];
-        ap[var[b[i] - 1]].insert(i);
+        b[i]--;
+        p[var[b[i]]].insert(i);
     }
 
-    int sz = n;
-    while (__builtin_popcount(sz) != 1) {
-        sz++;
+    vi df(n - 1);
+    int c = 0;
+    rep(i, n - 1) {
+        df[i] = *p[i + 1].begin() - *p[i].begin();
+        c += df[i] < 0;
     }
 
-    V<ordered_set<pair<int, int>>> seg(sz * 2);
-    vl sum(sz * 2);
-    nrep(i, sz, sz * 2) {
-        seg[i].insert({oo, i - sz});
-    }
-
-    for (int i = sz - 1; i > 0; i--) {
-        repv(j, seg[i * 2]) {
-            seg[i].insert(j);
-        }
-        repv(j, seg[i * 2 + 1]) {
-            seg[i].insert(j);
-        }
-    }
-
-    auto update = [&](int i, int v) {
-        int ind = i;
-        i += sz;
-        auto bf = *seg[i].begin();
-        seg[i].clear();
-        seg[i].insert({v, i - sz});
-        int now = i & 1;
-        int dd = 0;
-
-        for (i >>= 1; i > 0; i >>= 1) {
-            seg[i].erase(bf);
-            seg[i].insert({v, ind});
-            sum[i] += dd;
-
-            if (now) {
-                int s = seg[i * 2].size() - seg[i * 2].order_of_key({v, oo});
-                int s2 = seg[i * 2].size() - seg[i * 2].order_of_key({bf.first, oo});
-                sum[i] -= s2;
-                sum[i] += s;
-                dd -= s2;
-                dd += s;
-            } else {
-                int s = seg[i * 2 + 1].order_of_key({v, -1});
-                int s2 = seg[i * 2 + 1].order_of_key({bf.first, -1});
-                sum[i] -= s2;
-                sum[i] += s;
-                dd -= s2;
-                dd += s;
-            }
-
-            now = i & 1;
-        }
-    };
-
-    rep(i, n) {
-        update(i, *ap[i].begin());
-    }
-
-    auto check = [&]() {
     string ans[] = {
         "TIDAK",
         "YA"
     };
-        cout << ans[sum[1] == 0] << '\n';
+
+    cout << ans[c == 0] << '\n';
+
+    auto rem = [&](int i) {
+        if (i < n - 1 && df[i] < 0) {
+            c--;
+        }
+
+        if (i > 0 && df[i - 1] < 0) {
+            c--;
+        }
+    };
+
+    auto add = [&](int i) {
+        if (i < n - 1) {
+            df[i] = *p[i + 1].begin() - *p[i].begin();
+            c += df[i] < 0;
+        }
+
+        if (i > 0) {
+            df[i - 1] = *p[i].begin() - *p[i - 1].begin();
+            c += df[i - 1] < 0;
+        }
     };
 
-    check();
     while (q--) {
         int i, j;
         cin >> i >> j;
-        i--;
+        i--, j--;
 
         int bf = b[i];
         b[i] = j;
-        int actbf = var[bf - 1];
-        int actb = var[b[i] - 1];
+        j = var[j];
+        bf = var[bf];
+        rem(bf);
+        p[bf].erase(i);
+        add(bf);
+        rem(j);
+        p[j].insert(i);
+        add(j);
 
-        ap[actbf].erase(i);
-        ap[actb].insert(i);
-        update(actbf, *ap[actbf].begin());
-        update(actb, *ap[actb].begin());
-        check();
+        cout << ans[c == 0] << '\n';
     }
 }
 

Educational Codeforces Round 189 (Rated for Div. 2)/A. A Number Between Two Others.cpp

@@ -0,0 +1,111 @@
+/* Problem URL: https://codeforces.com/contest/2225/problem/A */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    ll x, y;
+    cin >> x >> y;
+
+    ll mod = y / x;
+
+    cout << (mod > 2 ? "YES\n" : "NO\n");
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Educational Codeforces Round 189 (Rated for Div. 2)/B. Alternating String.cpp

@@ -0,0 +1,153 @@
+/* Problem URL: https://codeforces.com/contest/2225/problem/B */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    string a;
+    cin >> a;
+    repv(i, a) {
+        i -= 'a';
+    }
+
+    int n = a.size();
+    vi one(n);
+    int now = 0;
+    rep(i, n) {
+        one[i] = a[i] == now;
+        now ^= 1;
+    }
+
+    vi two(n);
+    now = 1;
+    rep(i, n) {
+        two[i] = a[i] == now;
+        now ^= 1;
+    }
+
+    auto check = [&](vi &a) {
+        int i = 0;
+        while (i < n && a[i] == 0) {
+            i++;
+        }
+
+        if (i >= n) {
+            return true;
+        }
+
+        while (i < n && a[i] == 1) {
+            i++;
+        }
+
+        while (i < n && a[i] == 0) {
+            i++;
+        }
+
+        return i == n;
+    };
+
+    if (check(one) || check(two)) {
+        cout << "YES\n";
+        return;
+    }
+
+    cout << "NO\n";
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Educational Codeforces Round 189 (Rated for Div. 2)/C. Red-Black Pairs.cpp

@@ -0,0 +1,122 @@
+/* Problem URL: https://codeforces.com/contest/2225/problem/C */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    cin >> n;
+
+    string a[2];
+    cin >> a[0] >> a[1];
+
+    vi dp(n + 1);
+
+    nrep(i, 1, n + 1) {
+        int p = i - 1;
+        dp[i] = (a[0][p] != a[1][p]) + dp[i - 1];
+        if (i > 1) {
+            rmin(dp[i], (a[0][p] != a[0][p - 1]) + (a[1][p] != a[1][p - 1]) + dp[i - 2]);
+        }
+    }
+
+    cout << dp[n] << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Educational Codeforces Round 189 (Rated for Div. 2)/D. Exceptional Segments.cpp

@@ -0,0 +1,133 @@
+/* Problem URL: https://codeforces.com/contest/2225/problem/D */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    ll n, x;
+    cin >> n >> x;
+
+    const ll mod = 998244353;
+
+    auto calc = [&](ll n, ll x) {
+        if (x < 0) {
+            return 0LL;
+        }
+        ll ans = 0;
+        ll cur = x / 4;
+        if (cur >= 0) {
+            ll bf = cur +1;
+
+            ll m = x % 4;
+            ll up = x + 3 - m;
+            if (up <= n) {
+                ll diff = n - up;
+                diff = diff / 4 + 1;
+                bf %= mod;
+                diff %= mod;
+                ans = (bf * diff) % mod;
+            }
+        }
+        return ans;
+    };
+
+    cout << (calc(n, x) + calc(n - 2, x - 2)) % mod << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Ethflow Round 1 (Codeforces Round 1001, Div. 1 + Div. 2)/E1. The Game (Easy Version).cpp

@@ -0,0 +1,164 @@
+/* Problem URL: https://codeforces.com/problemset/problem/2062/E1 */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    cin >> n;
+    vl w(n);
+    ordered_set<pair<ll, int>> c;
+    priority_queue<pair<ll, int>> pq;
+    rep(i, n) {
+        cin >> w[i];
+        c.insert({w[i], i});
+        pq.emplace(w[i], i);
+    }
+
+    vvi graph(n);
+    rep(i, n - 1) {
+        int a, b;
+        cin >> a >> b;
+        a--, b--;
+        graph[a].push_back(b);
+        graph[b].push_back(a);
+    }
+
+    vi ac(n);
+    V<ordered_set<pair<ll, int>>> ev(n);
+
+    function<void(int, int)> dfs = [&](int i, int p) {
+        repv(j, graph[i]) {
+            if (j == p) {
+                continue;
+            }
+
+            dfs(j, i);
+
+            if (ev[j].size() > ev[i].size()) {
+                ev[i].swap(ev[j]);
+            }
+            
+            repv(k, ev[j]) {
+                ev[i].insert(k);
+            }
+        }
+
+        ac[i] = ev[i].size() - ev[i].order_of_key({w[i], oo});
+        ev[i].insert({w[i], i});
+    };
+
+    dfs(0, 0);
+
+    while (!pq.empty()) {
+        auto [wi, i] = pq.top();
+        pq.pop();
+
+        if (ac[i] == c.size() - c.order_of_key({wi, oo})) {
+            continue;
+        }
+        
+        cout << i + 1 << '\n';
+        return;
+    }
+
+    cout << "0\n";
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

IME++ Starters Try-outs 2023/J. Jagged Roads.cpp

@@ -0,0 +1,139 @@
+/* Problem URL: https://codeforces.com/gym/104415/problem/J */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 0
+
+void solve()
+{
+    int n, m;
+    cin >> n >> m;
+
+    V<V<pair<int, long double>>> graph(n);
+    while (m--) {
+        int a, b;
+        ll c;
+        cin >> a >> b >> c;
+        a--, b--;
+        graph[a].emplace_back(b, log(c) / log(7));
+        graph[b].emplace_back(a, log(c) / log(7));
+    }
+
+    priority_queue<pair<long double, int>, V<pair<long double, int>>, greater<>> pq;
+    V<long double> dis(n, 1e18L);
+    dis[0] = 0;
+    pq.emplace(0, 0);
+
+    while (!pq.empty()) {
+        auto [c, i] = pq.top();
+        pq.pop();
+        if (c > dis[i]) {
+            continue;
+        }
+
+        for (auto [j, w] : graph[i]) {
+            if (dis[j] > c + w) {
+                dis[j] = c + w;
+                pq.emplace(dis[j], j);
+            }
+        }
+    }
+
+    cout << fixed << setprecision(15) << dis[n - 1] << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Manthan, Codefest 18 (rated, Div. 1 + Div. 2)/D. Valid BFS?.cpp

@@ -0,0 +1,151 @@
+/* Problem URL: https://codeforces.com/problemset/problem/1037/D */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 0
+
+void solve()
+{
+    int n;
+    cin >> n;
+    vvi graph(n);
+    rep(i, n - 1) {
+        int a, b;
+        cin >> a >> b;
+        a--, b--;
+        graph[a].push_back(b);
+        graph[b].push_back(a);
+    }
+
+    vi ord(n);
+    cin >> ord;
+
+    vvi dict(n + 1);
+
+    function<void(int, int)> dfs = [&](int i, int p) {
+        repv(j, graph[i]) {
+            if (j == p) {
+                continue;
+            }
+
+            dict[i].push_back(j + 1);
+            dfs(j, i);
+        }
+        sortv(dict[i]);
+    };
+
+    dfs(0, 0);
+
+    int cur = 1;
+    rep(i, n) {
+        vi tmp;
+        rep(j, dict[ord[i] - 1].size()) {
+            tmp.push_back(ord[cur]);
+            cur++;
+        }
+
+        sortv(tmp);
+        if (tmp != dict[ord[i] - 1]) {
+            cout << "No\n";
+            return;
+        }
+    }
+
+    cout << "Yes\n";
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

Neowise Labs Contest 1 (Codeforces Round 1018, Div. 1 + Div. 2)/D. Wonderful Lightbulbs.cpp

@@ -0,0 +1,133 @@
+/* Problem URL: https://codeforces.com/problemset/problem/2096/D */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+const int oo = INT32_MAX >> 1;
+const ll OO = INT64_MAX >> 1;
+
+
+void pre()
+{
+
+}
+
+#define TEST 1
+
+void solve()
+{
+    int n;
+    cin >> n;
+    V<pair<ll, ll>> a(n);
+    map<ll, int> cx;
+    map<ll, int> cy;
+    repv(i, a) {
+        cin >> i.first >> i.second;
+        cx[i.first]++;
+        cy[i.first + i.second]++;
+    }
+
+    ll x;
+    repv(i, cx) {
+        if (i.second & 1) {
+            x = i.first;
+            break;
+        }
+    }
+
+    ll y;
+    repv(i, cy) {
+        if (i.second & 1) {
+            y = i.first;
+            break;
+        }
+    }
+
+    cout << x << ' '  << y - x << '\n';
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}

TODO.md

@@ -147,7 +147,7 @@ Official divs from codeforces
 		I honestly have no idea how to solve this, the editorial didn't help much, I'll get
 		back at it after learning NTT or something.
 	
-	- [ ] [C2. Adjust The Presentation (Hard Version)](https://codeforces.com/problemset/problem/2021/C2)
+	- [X] [C2. Adjust The Presentation (Hard Version)](https://codeforces.com/problemset/problem/2021/C2)
 
 		I already have the idea figured out, but my solution ended up getting TLE, I'll have to come
 		with something better.

problemlist.md

@@ -147,6 +147,10 @@ A little collection of interesting problems that I randomly decided to do.
 	A really easy problem, at least it is once you realize that it's just a tree and the
 	calculation is simple.
 
+- [E. Not Escaping](https://codeforces.com/problemset/problem/1627/E)
+
+	AMAZING graph problem, I actually had fun solving it.
+
 ## Math
 
 - [E2. Rudolf and Snowflakes (hard version)](https://codeforces.com/problemset/problem/1846/E2)