Submission #1092010

#	Time	Username	Problem	Language	Result	Execution time	Memory
1092010		dpsaveslives	Museum (CEOI17_museum)	C++17	100 / 100	624 ms	784468 KiB

museum

#include <bits/stdc++.h>
#define ll long long
#define f first
#define s second
using namespace std;
const int INF = 1e9;
const int MAXN = 1e4;
vector<pair<int,int>> adj[MAXN+1];
int dp[MAXN+1][MAXN+1][2];
int st[MAXN+1];
void calcst(int u, int par){
    st[u] = 1;
    for(auto p : adj[u]){
        if(p.f == par) continue;
        calcst(p.f,u);
        st[u] += st[p.f];
    }
}
void dfs(int u,int par){
    //dp[u][0][0] = dp[u][0][1] = dp[u][1][0] = dp[u][1][1] = 0;
    for(int cur = 1; auto p : adj[u]){
        if(p.f == par) continue;
        dfs(p.f,u);
        cur += st[p.f];
        for(int i = cur;i>=2;--i){
            for(int j = max(0,i-cur+st[p.f]);j<=min(i,st[p.f]);++j){
                //cout << i-j << " " << j << " " << dp[u][i-j][0] << " " << dp[u][i-j][1] << " " << dp[p.f][j][0] << " " << dp[p.f][j][1] << "\n";
                dp[u][i][0] = min(dp[u][i][0],dp[p.f][j][0]+dp[u][i-j][1]+p.s);
                dp[u][i][0] = min(dp[u][i][0],dp[p.f][j][1]+dp[u][i-j][0]+2*p.s);
                dp[u][i][1] = min(dp[u][i][1],dp[p.f][j][1]+dp[u][i-j][1]+2*p.s);
                //cout << u << " " << i << " " << dp[u][i][0] << " " << dp[u][i][1] << "\n";
            }
        }

    }
}
int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int N,K,X; cin >> N >> K >> X;
    for(int i = 0;i<=N-2;++i){
        int a,b,c; cin >> a >> b >> c;
        adj[a].push_back({b,c}); adj[b].push_back({a,c});
    }
    for(int i = 1;i<=N;++i){
        for(int j = 2;j<=N;++j){
            dp[i][j][0] = dp[i][j][1] = INF;
        }
    }

    calcst(X,-1);
    dfs(X,-1);
    cout << dp[X][K][0] << "\n";
    return 0;
}

Compilation message (stderr)

museum.cpp: In function 'void dfs(int, int)':
museum.cpp:21:22: warning: range-based 'for' loops with initializer only available with '-std=c++2a' or '-std=gnu++2a'
   21 |     for(int cur = 1; auto p : adj[u]){
      |                      ^~~~

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