More stuff

2026-04-08 14:42:50 -03:00
parent a588dcb40a
commit 704b6fec60
11 changed files with 1445 additions and 0 deletions
--- a/Wisdom.cpp
+++ b/Wisdom.cpp
@@ -0,0 +1,200 @@
+/* Problem URL: https://codeforces.com/problemset/problem/2034/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;
+    vi a(n);
+    cin >> a;
+
+    array<int, 3> c = {0, 0, 0};
+    set<int> o;
+    rep(i, n) {
+        c[a[i]]++;
+        if (a[i] == 1) {
+            o.insert(i);
+        }
+    }
+
+    V<pair<int, int>> ans;
+
+    auto printans = [&]() {
+        cout << ans.size() << '\n';
+        repv(i, ans) {
+            cout << i.first << ' ' << i.second << '\n';
+        }
+    };
+
+    nrep(i, c[0], c[0] + c[1]) {
+        if (a[i] == 1) {
+            o.erase(i);
+            continue;
+        }
+    }
+
+    int val = -1;
+    nrep(i, c[0], c[0] + c[1]) {
+        if (o.empty()) {
+            break;
+        }
+
+        if (a[i] != 1) {
+            if (o.size() == 1) {
+                val = i;
+                break;
+            }
+            swap(a[*o.begin()], a[i]);
+            ans.emplace_back(*o.begin() + 1, i + 1);
+            o.erase(o.begin());
+        }
+    }
+
+    set<int> t;
+    set<int> z;
+    rep(i, c[0]) {
+        if (a[i] > 1) {
+            t.insert(i);
+        }
+    }
+
+    nrep(i, c[0] + c[1], n) {
+        if (a[i] < 1){
+            z.insert(i);
+        }
+    }
+
+    int ch = c[0];
+    if (!o.empty()) {
+        ch = *o.begin();
+    } else {
+        if (t.empty() || z.empty()) {
+            cout << "0\n";
+            return;
+        }
+
+        ans.emplace_back(*t.begin() + 1, c[0] + 1);
+        val = c[0];
+        ch = *t.begin();
+        t.erase(t.begin());
+    }
+
+    int now = ch > c[0];
+    while (!t.empty() || !z.empty()) {
+        if (now) {
+            ans.emplace_back(*t.begin() + 1, ch + 1);
+            ch = *t.begin();
+            t.erase(t.begin());
+            now ^= 1;
+            continue;
+        }
+
+        ans.emplace_back(*z.begin() + 1, ch + 1);
+        ch = *z.begin();
+        z.erase(z.begin());
+        now ^= 1;
+    }
+
+    ans.emplace_back(ch + 1, val + 1);
+
+    printans();
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    pre();
+
+    int t;
+    (TEST && cin >> t) || (t = 1);
+    while (t--) {
+        solve();
+    }
+}