Submission #894320

#	Time	Username	Problem	Language	Result	Execution time	Memory
894320		juliany2	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	179 ms	2644 KiB

Main

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(x) (x).begin(), (x).end()

const int N = 507;
int n, k;
array<int, 2> a[N];
double dp[N][N];

int main() {
    cin.tie(0)->sync_with_stdio(false);

    cin >> n >> k;

    for (int i = 1; i <= n; i++) {
        cin >> a[i][0] >> a[i][1];
        if (a[i][1] == -1)
            a[i][1] = 1e9;
    }

    sort(a + 1, a + n + 1, [&](array<int, 2> &x, array<int, 2> &y) { return x[1] < y[1]; });

    double ans = 1e9;
    for (int c = 0; c <= k; c++) {
        for (int i = 0; i <= n; i++)
            for (int j = 0; j <= n; j++)
                dp[i][j] = 1e9;

        dp[0][0] = 0;

        for (int i = 1; i <= n; i++) {
            for (int j = 0; j < i; j++) {
                if (j < k - c)
                    dp[i][j + 1] = min(dp[i][j + 1], dp[i - 1][j] + (double) a[i][0] / (c + 1));
                if (i - j - 1 < c && a[i][1] < 1e9)
                    dp[i][j] = min(dp[i][j], dp[i - 1][j] + (double) a[i][1] / (i - j));
                if (i - j - 1 >= c)
                    dp[i][j] = min(dp[i][j], dp[i - 1][j]);
            }
        }

        ans = min(ans, dp[n][k - c]);
    }

    cout << fixed << setprecision(10) << ans << '\n';

    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