Submission #890648

#	Time	Username	Problem	Language	Result	Execution time	Memory
890648		arbuzick	Let's Win the Election (JOI22_ho_t3)	C++17	56 / 100	2896 ms	1048576 KiB

Main

#pragma GCC optimize("O3")
#include <bits/stdc++.h>

using namespace std;

constexpr int maxn = 101, inf = 1e9 + 7;

double dp[maxn][maxn][maxn][maxn];

void solve() {
    int n, k;
    cin >> n >> k;
    vector<double> a(n), b(n);
    vector<pair<double, int>> s_b;
    for (int i = 0; i < n; ++i) {
        cin >> a[i] >> b[i];
        if (b[i] > 0) {
            s_b.emplace_back(b[i], i);
        } else {
            s_b.emplace_back(inf, i);
        }
    }
    sort(s_b.begin(), s_b.end());
    for (int i = 0; i <= n; ++i) {
        for (int cnt_all = 0; cnt_all < k; ++cnt_all) {
            for (int cnt_nw = 0; cnt_nw <= i && cnt_nw <= cnt_all; ++cnt_nw) {
                for (int cnt_used = 0; cnt_used <= k; ++cnt_used) {
                    dp[i][cnt_all][cnt_nw][cnt_used] = inf;
                }
            }
        }
    }
    for (int cnt_all = 0; cnt_all < k; ++cnt_all) {
        dp[0][cnt_all][0][0] = 0;
    }
    double ans = inf;
    for (int i = 0; i < n; ++i) {
        for (int cnt_all = 0; cnt_all < k; ++cnt_all) {
            for (int cnt_nw = 0; cnt_nw <= i && cnt_nw <= cnt_all; ++cnt_nw) {
                for (int cnt_used = 0; cnt_used < k; ++cnt_used) {
                    if (s_b[i].first < 10000 && cnt_nw < cnt_all) {
                        dp[i + 1][cnt_all][cnt_nw + 1][cnt_used + 1] = min(dp[i + 1][cnt_all][cnt_nw + 1][cnt_used + 1], dp[i][cnt_all][cnt_nw][cnt_used] + s_b[i].first / (cnt_nw + 1));
                        if (cnt_used + 1 == k && cnt_nw + 1 == cnt_all) {
                            ans = min(ans, dp[i + 1][cnt_all][cnt_nw + 1][cnt_used + 1]);
                        }
                    }
                    dp[i + 1][cnt_all][cnt_nw][cnt_used + 1] = min(dp[i + 1][cnt_all][cnt_nw][cnt_used + 1], dp[i][cnt_all][cnt_nw][cnt_used] + a[s_b[i].second] / (cnt_all + 1));
                    if (cnt_used + 1 == k && cnt_nw == cnt_all) {
                        ans = min(ans, dp[i + 1][cnt_all][cnt_nw][cnt_used + 1]);
                    }
                    dp[i + 1][cnt_all][cnt_nw][cnt_used] = min(dp[i + 1][cnt_all][cnt_nw][cnt_used], dp[i][cnt_all][cnt_nw][cnt_used]);
                }
            }
        }
    }
    cout << ans << '\n';
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.precision(25);
    cout << fixed;
    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}

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