Submission #1297225

#	Time	Username	Problem	Language	Result	Execution time	Memory
1297225		nguyenkhangninh99	Museum (CEOI17_museum)	C++20	20 / 100	183 ms	392772 KiB

museum

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

#define int long long

const int maxn = 5e3 + 5;

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

void minimize(int &a, int b){
    a = min(a, b);
}

void dfs(int u, int p) {
    sz[u] = 1;
    dp[u][1][0] = dp[u][0][0] = 0;
    dp[u][1][1] = -sum[u];
    for (auto [v, w]: adj[u]) {
        if (v == p) continue;
        sum[v] = sum[u] + w;
        dfs(v, u);
        for (int i = sz[u]; i >= 0; i--){
            for (int j = 0; j <= sz[v]; j++) {
                int add = 2 * w * (j > 0);
                minimize(dp[u][i + j][0], dp[u][i][0] + dp[v][j][0] + add);
                minimize(dp[u][i + j][1], min(dp[u][i][0] + dp[v][j][1], dp[u][i][1] + dp[v][j][0]) + add);
            }
        }
        
        sz[u] += sz[v];
    }
}

void solve(){
    int n, k, x; cin >> n >> k >> x;
    for (int i = 1; i <= n - 1; i++){
        int u, v, w; cin >> u >> v >> w;
        adj[u].push_back({v, w});
        adj[v].push_back({u, w});
    }
    
    memset(dp, 0x3f, sizeof(dp));
    dfs(x, 0);
    cout << dp[x][k][1] << '\n';
}

signed main() {
    ios::sync_with_stdio(false);  
	cin.tie(0); cout.tie(0);
    
    solve();
}

• Subtask 1: 20 / 20
• Subtask 2: 0 / 25
• Subtask 3: 0 / 35
• Subtask 4: 0 / 20