1474C - Array Destruction - CodeForces Solution

#include <bits/stdc++.h>

using namespace std;
using ll = long long;

int main() {
    ios_base::sync_with_stdio(false); 
    cin.tie(nullptr);
    ll tests = 1; 
    cin >> tests;
    while (tests-- > 0) {
        int n;
        cin >> n;
        vector <ll> a(2 * n);
        for (int i = 0; i < 2 * n; ++i) {
            cin >> a[i];
        }
        sort (a.begin(), a.end());
        bool ok = 0;
        for (int i = 0; i < 2 * n - 1; ++i) {
            int x = a[i] + a[2 * n - 1];
            multiset <int> s;
            vector <pair <int, int>> res;
            for (int j = 0; j < 2 * n; ++j) {
                s.insert(a[j]);
            }
            for (int j = 0; j < n; ++j) {
                auto it = --s.end();
                int mx = *it;
                s.erase(it);
                it = s.find(x - mx);
                if (it == s.end()) {
                    break;
                }
                res.push_back({x - mx, mx});
                x = mx;
                s.erase(it);
            }
            if (res.size() == n) {
                ok = 1;
                cout << "YES\n";
                cout << a[i] + a[2 * n - 1] << "\n";
                for (auto &[x, y] : res) {
                    cout << x << " " << y << "\n";
                }
                break;
            }
        }
        if (!ok) {
            cout << "NO\n";
        }
    }
}