Submission #951981

#	Time	Username	Problem	Language	Result	Execution time	Memory
951981		GrandTiger1729	Cake 3 (JOI19_cake3)	C++17	0 / 100	1 ms	452 KiB

cake3

#include <bits/stdc++.h>
using namespace std;

const long long INF = 1e18;
int main()
{
    cin.tie(0)->sync_with_stdio(0);
    int n, K;
    cin >> n >> K;
    vector<pair<int, int>> a(n);
    for (int i = 0; i < n; i++)
    {
        cin >> a[i].second >> a[i].first;
    }
    sort(a.begin(), a.end());
    long long ans = -INF;
    function<void(int, int, int, int)> solve = [&](int l, int r, int ql, int qr)
    {
        if (l > r || ql > qr || ql == -1 || qr == -1)
        {
            return;
        }
        int mid = (l + r) / 2;
        pair<long long, int> maxn(-INF, -1);
        long long cur = 0;
        priority_queue<int, vector<int>, greater<>> pq;
        int i = mid;
        for (; i > qr; i--)
        {
            pq.push(a[i].second);
            cur += a[i].second;
        }
        for (; i >= ql; i--)
        {
            pq.push(a[i].second);
            cur += a[i].second;
            while (pq.size() > K)
            {
                cur -= pq.top();
                pq.pop();
            }
            if (pq.size() == K)
            {
                maxn = max(maxn, make_pair(cur - 2ll * (a[mid].first - a[i].first), i));
            }
        }
        ans = max(ans, maxn.first);
        solve(l, mid - 1, ql, maxn.second);
        solve(mid + 1, r, maxn.second, qr);
    };
    solve(0, n - 1, 0, n - 1);
    cout << ans << '\n';
    return 0;
}

Compilation message (stderr)

cake3.cpp: In lambda function:
cake3.cpp:37:30: warning: comparison of integer expressions of different signedness: 'std::priority_queue<int, std::vector<int>, std::greater<void> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   37 |             while (pq.size() > K)
      |                    ~~~~~~~~~~^~~
cake3.cpp:42:27: warning: comparison of integer expressions of different signedness: 'std::priority_queue<int, std::vector<int>, std::greater<void> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   42 |             if (pq.size() == K)
      |                 ~~~~~~~~~~^~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 19
• Subtask 3: 0 / 76