Submission #378640

#	Time	Username	Problem	Language	Result	Execution time	Memory
378640		syl123456	Gift (IZhO18_nicegift)	C++17	30 / 100	2085 ms	344060 KiB

nicegift

#include <bits/stdc++.h>
#define all(i) i.begin(), i.end()
#define rall(i) i.rbegin(), i.rend()
using namespace std;
typedef long long ll;
typedef pair<int, int> pi;
typedef pair<ll, int> pl;
int main() {
    ios::sync_with_stdio(0), cin.tie(0);
    int n, k;
    cin >> n >> k;
    ll a[n], sum = 0, mx = 0;
    priority_queue<pl> pq;
    for (int i = 0; i < n; ++i) cin >> a[i], sum += a[i], mx = max(mx, a[i]), pq.emplace(a[i], i);
    if (sum % k != 0 || mx > sum / k) return cout << -1, 0;
    vector<int> v;
    vector<vector<int>> ans;
    while (sum > 0) {
        for (int i = 0; i < k; ++i)
            v.push_back(pq.top().second), pq.pop();
        if (a[v.back()] == sum / k) {
            ans.emplace_back(1, sum / k);
            for (int i : v) ans.back().push_back(i + 1);
            break;
        }
        ll x = max(1ll, a[v.back()] - pq.top().first);
        ans.emplace_back(1, x);
        while (!v.empty()) {
            int i = v.back();
            v.pop_back();
            ans.back().push_back(i + 1);
            a[i] -= x, sum -= x;
            pq.emplace(a[i], i);
        }
    }
    cout << ans.size() << '\n';
    for (auto i : ans) {
        for (int j : i) cout << j << ' ';
        cout << '\n';
    }
}
/*
 * sum % k == 0 && max <= sum / k
 * always sort 321
 * every time [0,k), x = max(h[k] - h[k-1], 1)
 */

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