Submission #1213149

#	Time	Username	Problem	Language	Result	Execution time	Memory
1213149		trimkus	Closing Time (IOI23_closing)	C++20	75 / 100	1041 ms	2162688 KiB

closing

#include "closing.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int max_score(int N, int X, int Y, long long K,
              std::vector<int> U, std::vector<int> V, std::vector<int> _W)
{
    vector<vector<pair<int, int>>> adj(N);
    for (int i = 0; i < N - 1; ++i) {
        adj[U[i]].push_back({V[i], _W[i]});
        adj[V[i]].push_back({U[i], _W[i]});
    }
    vector<vector<ll>> dist(2, vector<ll>(N));
    auto dfs = [&](auto& dfs, int v, int p, int i) -> void {
        for (auto& [u, w] : adj[v]) {
            if (u == p) continue;
            dist[i][u] = dist[i][v] + w;
            dfs(dfs, u, v, i);
        }
    };
    
    dfs(dfs, X, -1, 0);
    dfs(dfs, Y, -1, 1);
    vector<array<ll, 2>> cost;
    for (int i = 0; i < N; ++i) {
        ll c1 = min(dist[0][i], dist[1][i]);
        ll c2 = max(dist[0][i], dist[1][i]);
        cost.push_back({c1, i});
        cost.push_back({c2, i});
    }
    ll tot = 0;
    int res = 0;
    vector<bool> vis(N);
    sort(begin(cost), end(cost));
    for (int i = 0; i < (int)cost.size(); ++i) {
        ll c = cost[i][0];
        int j = cost[i][1];
        if (vis[j]) {
            c -= min(dist[0][j], dist[1][j]);
        }
        if (tot + c <= K) {
            tot += c;
            res += 1;
            vis[j] = true;
        } else {
            break;
        }
    }
    // cerr << "res = " <<res << "\n";
    // cerr << "Now dp:\n";
    
    const ll INF = 1e18;
    vector<vector<ll>> dp(N + 1, vector<ll>(2 * N + 5, INF));
    dp[0][0] = 0;
    // res = 0;
    for (int i = 0; i < N; ++i) {
        for (int j = 0; j <= 2 * N; ++j) {
            if (dist[0][i] + dist[1][i] == dist[0][Y]) {
                dp[i + 1][j + 1] = min(dp[i + 1][j + 1], dp[i][j] + min(dist[0][i], dist[1][i]));
                dp[i + 1][j + 2] = min(dp[i + 1][j + 2], dp[i][j] + max(dist[0][i], dist[1][i]));
                continue;
            }
            dp[i + 1][j] = min(dp[i + 1][j], dp[i][j]);
            dp[i + 1][j + 1] = min(dp[i + 1][j + 1], dp[i][j] + min(dist[0][i], dist[1][i]));
            dp[i + 1][j + 2] = min(dp[i + 1][j + 2], dp[i][j] + max(dist[0][i], dist[1][i]));
        }
        // for (int j = 0; j <= 2 * N; ++j) {
        //     cerr << setw(4) << left;
        //     if (dp[i][j] > K) cerr << "- ";
        //     else cerr << dp[i][j] << " ";
        // }
        // cerr << "\n";
    }
    // for (int j = 0; j <= 2 * N; ++j) {
    //         cerr << setw(4) << left;
    //         if (dp[N][j] > K) cerr << "- ";
    //         else cerr << dp[N][j] << " ";
    //     }
    //     cerr << "\n";
    for (int i = 0; i <= 2 * N; ++i) {
        
        if (dp[N][i] <= K) {
            res = max(res, i);
        }
    }
    return res;
}

• Subtask 0: 0 / 0
• Subtask 1: 0 / 8
• Subtask 2: 9 / 9
• Subtask 3: 12 / 12
• Subtask 4: 14 / 14
• Subtask 5: 9 / 9
• Subtask 6: 11 / 11
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 0 / 17