Submission #879948

#	Time	Username	Problem	Language	Result	Execution time	Memory
879948		frostray8653	Let's Win the Election (JOI22_ho_t3)	C++17	10 / 100	232 ms	5080 KiB

Main

#include <bits/stdc++.h>
#define int long long
#define IO ios::sync_with_stdio(0), cin.tie(0)
#define FOR(i, a, b) for (int i = a; i <= b; i++)
using namespace std;
using pii = pair<int, int>;

const int N = 505;
const int INF = 1e15;
const double dINF = 1e15;
pii a[N];

signed main() {
    IO;
    
    int n, tar;
    cin >> n >> tar;
    FOR(i, 1, n) {
        cin >> a[i].first >> a[i].second;
        if (a[i].second == -1)
            a[i].second = INF;
    }
    sort(a + 1, a + n + 1, [&](pii p, pii q) {
        if (p.second != q.second)
            return p.second < q.second;
        return p.first < q.first;
    });
    vector<vector<double>> dp(n + 1, vector<double>(n + 1, dINF));
    dp[0][0] = 0;
    for (int i = 1; i <= n; i++) {
        vector<vector<double>> ndp(n + 1, vector<double>(n + 1, dINF));
        for (int j = 0; j < i; j++) {
            for (int k = 0; k <= j; k++) {
                if (dp[j][k] < dINF) {
                    ndp[j][k] = min(ndp[j][k], dp[j][k]);
                    if (a[i].second < INF)
                        ndp[j + 1][k + 1] = min(ndp[j + 1][k + 1], dp[j][k] + (double)a[i].second / (k + 1));
                    ndp[j + 1][k] = min(ndp[j + 1][k], dp[j][k] + (double)a[i].first / (k + 1));
                }
            }
        }
        swap(dp, ndp);
    }
    double ans = dINF;
    for (int k = 0; k <= n; k++)
        ans = min(ans, dp[tar][k]);
    cout << fixed << setprecision(10) << ans << "\n";

    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 0 / 11
• Subtask 4: 0 / 12
• Subtask 5: 0 / 33
• Subtask 6: 0 / 11
• Subtask 7: 0 / 23