Add a lot more problems and a TODO list

Codeforces Round 824 (Div. 2)/D. Meta-set.cpp

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+/* Problem URL: https://codeforces.com/problemset/problem/1735/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;
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int n, k;
+    cin >> n >> k;
+
+    vvi fds(n, vi(k));
+    cin >> fds;
+
+    map<ll, int> pos;
+
+    int prox[3][3];
+    prox[0][0] = 0;
+    prox[0][1] = 2;
+    prox[0][2] = 1;
+    prox[1][0] = 2;
+    prox[1][1] = 1;
+    prox[1][2] = 0;
+    prox[2][0] = 1;
+    prox[2][1] = 0;
+    prox[2][2] = 2;
+
+    auto convert = [&](vi &a) {
+        ll now = 0;
+        ll p = 1;
+
+        repv(i, a) {
+            now += i * p;
+            p *= 3;
+        }
+
+        return now;
+    };
+
+    auto getnext = [&](vi &a, vi &b) {
+        ll now = 0;
+        ll p = 1;
+
+        rep(i, k) {
+            now += prox[a[i]][b[i]] * p;
+            p *= 3;
+        }
+
+        return now;
+    };
+
+    rep(i, n) {
+        pos[convert(fds[i])] = i;
+    }
+
+    vi next(k);
+
+    ll ans = 0;
+
+    rep(i, n) {
+        ll cnt = 0;
+        // ll prev = 0;
+        rep(j, n) {
+            if (j == i) {
+                continue;
+            }
+            auto itr = pos.find(getnext(fds[i], fds[j]));
+            if (itr == pos.end() || itr->second < j) {
+                continue;
+            }
+            cnt++;
+        }
+
+        if (cnt < 2) {
+            continue;
+        }
+
+        ans += cnt * (cnt - 1) / 2;
+    }
+
+    cout << ans << '\n';
+}