Submission #1252187

#	Time	Username	Problem	Language	Result	Execution time	Memory
1252187		rayan_bd	Museum (CEOI17_museum)	C++20	100 / 100	444 ms	746340 KiB

museum

#include <bits/stdc++.h>
using namespace std;

const int mxN = 1e4 + 5;
const int INF = 1e9;

int dp[mxN][mxN][2], sz[mxN];
vector<pair<int, int>> adj[mxN];

void dfs(int u = 1, int par = -1){
    dp[u][1][0] = dp[u][1][1] = 0;
    sz[u] = 1;
    for(auto [v, c] : adj[u]){
        if(v ^ par){
            dfs(v, u);
            for(int i = sz[u]; i >= 1; --i){
                for(int j = sz[v]; j >= 1; --j){
                    dp[u][i + j][0] = min(dp[u][i + j][0], dp[u][i][0] + dp[v][j][0] + 2 * c);
                    dp[u][i + j][1] = min(dp[u][i + j][1], dp[u][i][1] + dp[v][j][0] + 2 * c);
                    dp[u][i + j][1] = min(dp[u][i + j][1], dp[u][i][0] + dp[v][j][1] + c);
                }
            }
            sz[u] += sz[v];
        }
    }
}

int main(){
   
    ios_base::sync_with_stdio(0);
    cin.tie(nullptr); cout.tie(nullptr);


    int n, k, x, u, v, c;
    cin >> n >> k >> x;

    for(int i = 1; i <= n - 1; ++i){
        cin >> u >> v >> c;
        adj[u].push_back({v, c});
        adj[v].push_back({u, c});
    }

    for(int i = 1; i <= n; ++i) for(int j = 0; j <= k; ++j) dp[i][j][0] = dp[i][j][1] = INF;

    dfs(x, -1);

    cout << min(dp[x][k][0], dp[x][k][1]) << "\n";

    return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 25 / 25
• Subtask 3: 35 / 35
• Subtask 4: 20 / 20