Submission #631195

#	Time	Username	Problem	Language	Result	Execution time	Memory
631195		Ooops_sorry	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	1673 ms	1038836 KiB

Main

#include<bits/stdc++.h>

using namespace std;

mt19937 rnd(51);

#define ll long long
#define pb push_back
#define ld double

const int N = 510, INF = 1e9;
int a[N], b[N], n, k;
ld dp[N][N][N];
vector<int> ord;

ld solve(int cnt) {
    dp[0][0][1] = 0;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j <= i; j++) {
            if (i == j) {
                for (int k = 1; k <= i + 1; k++) {
                    dp[i + 1][j][k] = min(dp[i + 1][j][k], dp[i][j][k]);
                    dp[i + 1][j + 1][k + 1] = min(dp[i + 1][j + 1][k + 1], dp[i][j][k] + (ld)b[ord[i]] / (ld)k);
                    dp[i + 1][j + 1][k] = min(dp[i + 1][j + 1][k], dp[i][j][k] + (ld)a[ord[i]] / (ld)cnt);
                }
            } else {
                dp[i + 1][j][cnt] = min(dp[i + 1][j][cnt], dp[i][j][cnt]);
                dp[i + 1][j + 1][cnt] = min(dp[i + 1][j + 1][cnt], dp[i][j][cnt] + (ld)a[ord[i]] / (ld)cnt);
            }
        }
    }
    return dp[n][k][cnt];
}

signed main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
#endif // LOCAL
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            for (int k = 0; k < N; k++) {
                dp[i][j][k] = INF;
            }
        }
    }
    cin >> n >> k;
    ord.resize(n);
    iota(ord.begin(), ord.end(), 0);
    for (int i = 0; i < n; i++) {
        cin >> a[i] >> b[i];
        if (b[i] == -1) {
            b[i] = INF;
        }
    }
    sort(ord.begin(), ord.end(), [&](int i, int j){return b[i] < b[j] || (b[i] == b[j] && a[i] < a[j]);});
    ld ans = INF;
    for (int i = 1; i <= k + 1; i++) {
        ans = min(ans, solve(i));
    }
    cout << setprecision(30) << fixed << ans << endl;
    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