Submission #172906

#	Time	Username	Problem	Language	Result	Execution time	Memory
172906		elitewantsyou	Gift (IZhO18_nicegift)	C++14	100 / 100	1165 ms	88452 KiB

nicegift

#include <bits/stdc++.h>

//#pragma GCC optimize("Ofast")

#define fi first
#define se second

const int N = 1000010;

using namespace std;

int n;
int k;
long long a[N];

int main()
{
        //freopen("input.txt", "r", stdin);
        //freopen("output.txt", "w", stdout);

        ios_base::sync_with_stdio(0);

        cin >> n >> k;
        priority_queue < pair < long long, int > > s;
        long long S = 0;
        for(int i = 1; i <= n; i++){
                cin >> a[i];
                s.push({a[i], i});

                S += a[i];
        }

        if(1ll * s.top().fi > S / k || S % k){
                cout << -1 << "\n";
                return 0;
        }

        vector < long long > qu;
        vector < vector < int > > res;
        vector < int > v;
        while(s.size() > 0){
                v.clear();
                for(int i = 0; i < k; i++){
                        v.push_back(s.top().se);
                        s.pop();
                }
                long long rem = 0;
                if(!s.empty()){
                        rem = s.top().fi;
                }
                long long l = 1, dif = a[v[0]] - rem;
                if(rem <= (S - dif * k) / k){
                        l = (S - rem * k) / k;
                        l = min(l, a[v.back()]);
                } else{
                        assert(0);
                }

                S -= k * l;
                res.push_back(v);
                qu.push_back(l);
                for(int i: v){
                        a[i] -= l;
                        if(!a[i]){
                                continue;
                        }
                        s.push({a[i], i});
                }
        }
        cout << qu.size() << "\n";
        for(int i = 0; i < qu.size(); i++){
                cout << qu[i];
                for(int x: res[i]){
                        cout << " " << x;
                }
                cout << "\n";
        }

}

Compilation message (stderr)

nicegift.cpp: In function 'int main()':
nicegift.cpp:71:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i = 0; i < qu.size(); i++){
                        ~~^~~~~~~~~~~

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