Submission #861591

#	Time	Username	Problem	Language	Result	Execution time	Memory
861591		PagodePaiva	Gift (IZhO18_nicegift)	C++17	7 / 100	206 ms	32684 KiB

nicegift

#include<bits/stdc++.h>

using namespace std;

int main(){
    int n, k;
    cin >> n >> k;

    priority_queue <pair <int, int>> pq;

    for(int i = 0;i < n;i++){
        int x;
        cin >> x;
        pq.push({x, i});
    }

    vector <array <int, 3>> resp;

    while(!pq.empty()){
        if(pq.size() == 1){
            cout << -1 << '\n';
            return 0;
        }

        if(pq.size() == 2){
            auto [a1, p1] = pq.top();
            pq.pop();
            auto [a2, p2] = pq.top();
            pq.pop();

            if(a1 != a2){
                cout << -1 << '\n';
                return 0;
            }

            resp.push_back({a1, p1, p2});
            break;
        }

        if(pq.size() == 3){
            auto [a1, p1] = pq.top();
            pq.pop();
            auto[a2, p2] = pq.top();
            pq.pop();
            auto [a3, p3] = pq.top();

            pq.pop();

            if(!(a1 != a2 or a1 != a3)){
                if(a1 % 2 != 0){
                    cout << "-1\n";
                    return 0;
                }

                resp.push_back({a1/2, p1, p2});
                resp.push_back({a1/2, p1, p3});
                resp.push_back({a1/2, p2, p3});

                break;
            }

            pq.push({a1, p1});
            pq.push({a2, p2});
            pq.push({a3, p3});
        }

        auto [val, pos] = pq.top();
        pq.pop();

        auto [val2, pos2] = pq.top();
        pq.pop();

        val -= val2;

        resp.push_back({val2, pos, pos2});

        if(val != 0) pq.push({val, pos});
    }


    cout << resp.size()<< '\n';

    for(auto x : resp){
        cout << x[0] << ' ' << x[1]+1 << ' ' << x[2]+1 << '\n';
    }

    return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 0 / 11
• Subtask 3: 0 / 12
• Subtask 4: 0 / 19
• Subtask 5: 0 / 51