[Advanced/C++/1017] Suggestion

[xwcai98]

虽然同样使用了优先队列记录结束时间，但是优先队列其实不需要初始化，我认为以下写法更加优秀。

#include <bits/stdc++.h>
using namespace std;
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    const int st = 8 * 3600, en = 17 * 3600;
    int n, k;
    cin >> n >> k;
    vector<pair<int, int>> a;
    for (int i = 0; i < n; ++i) {
        string time;
        int op;
        cin >> time >> op;
        int t = stoi(time.substr(0, 2)) * 3600 + 
            stoi(time.substr(3, 2)) * 60 + stoi(time.substr(6, 2));
        if (t >= en) continue;
        a.emplace_back(t, min(op * 60, 3600));
    }
    sort(a.begin(), a.end());
    int tot = 0, now = st;
    priority_queue<int, vector<int>, greater<int>> q;
    for (auto e: a) {
        now = max(now, e.first);
        while (!q.empty() && q.top() <= now) q.pop();
        if (q.size() == k) {
            now = max(now, q.top());
            q.pop();
        }
        q.push(now + e.second);
        tot += now - e.first;
    }
    int cnt = a.size();
    cout << fixed << setprecision(1) << tot / 60.0 / cnt << '\n';
    return 0;
}