Submission #1085016

#	Time	Username	Problem	Language	Result	Execution time	Memory
1085016		GasmaskChan	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	148 ms	2552 KiB

Main

#include <bits/stdc++.h>

using namespace std;
#define int long long

const int MAX = 5e2 + 5;

void minimize(double &a, const double &b) {
    a = min(a, b);
}

int sum[MAX][MAX];
double f[2][MAX];
pair<int, int> state[MAX];
int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    // freopen("test.inp", "r", stdin); freopen("test.out", "w", stdout);
    int n, k;
    cin >> n >> k;
    int g = 0;
    for (int i = 1; i <= n; i++) {
        cin >> state[i].first >> state[i].second;
        if (state[i].second == -1) state[i].second = 1e9;
        else ++g;
    }

    sort(state + 1, state + n + 1, [](const pair<int, int> &a, const pair<int, int> &b) -> bool {
        if (a.second != b.second) return a.second < b.second;
        return a.first < b.first;
    });

    memset(sum, 0x3f, sizeof sum);

    for (int i = 1; i <= n; i++) {
        sum[i][0] = 0;
        for (int j = i; j <= n; j++) {
            for (int z = k; z > 0; z--) {
                sum[i][z] = min(sum[i][z], sum[i][z - 1] + state[j].first);
            }
        }
    }

    sum[n + 1][0] = 0;

    double ans = sum[1][k];

    g = min(g, k);
    for (int c = 0; c <= g; c++) {
        for (int i = 0; i < 2; i++) {
            for (int j = 0; j <= k; j++) {
                f[i & 1][j] = 1e9;
            }
        }

        f[0][0] = 0.0;
        for (int i = 1; i <= k; i++) {
            for (int j = 0; j <= i; j++) {
                f[i & 1][j] = f[(i - 1) & 1][j] + 1.0 * state[i].first / (c + 1);
                if (j) minimize(f[i & 1][j], f[(i - 1) & 1][j - 1] + 1.0 * state[i].second / j);
                if (j == c) {
                    minimize(ans, f[i & 1][j] + 1.0 * sum[i + 1][k - i] / (c + 1));
                }
            }
        }
    }

    cout << fixed << ans;
    return 0;
}

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