#include<bits/stdc++.h>
using namespace std;
const int N=1e4+5;
int n,k,x,son[N];
int dp[N][N][2];
vector<pair<int,int> >g[N];
inline void dfs(int u,int fa){
dp[u][1][0]=dp[u][1][1]=0;
son[u]=1;
for(auto v:g[u]){
if(v.first==fa)continue;
dfs(v.first,u);
son[u]+=son[v.first];
for(int j=1;j<=min(son[v.first],k);j++){
for(int i=min(k,son[u]-son[v.first]+j);i>=j+1;i--){
if(dp[u][i-j][0]+dp[v.first][j][0]+v.second*2>=0)dp[u][i][0]=min(dp[u][i][0],dp[u][i-j][0]+dp[v.first][j][0]+v.second*2);
if(dp[u][i-j][0]+dp[v.first][j][1]+v.second>=0)dp[u][i][1]=min(dp[u][i][1],dp[u][i-j][0]+dp[v.first][j][1]+v.second);
if(dp[u][i-j][1]+dp[v.first][j][0]+v.second*2>=0)dp[u][i][1]=min(dp[u][i][1],dp[u][i-j][1]+dp[v.first][j][0]+v.second*2);
}
}
}
}
int main(){
//freopen("museum.in","r",stdin);
//freopen("museum.out","w",stdout);
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
memset(dp,0x7f,sizeof dp);
cin>>n>>k>>x;
for(int i=1,a,b,c;i<n;i++){
cin>>a>>b>>c;
g[a].push_back({b,c});
g[b].push_back({a,c});
}
dfs(x,-1);
cout<<min(dp[x][k][0],dp[x][k][1]);
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
355 ms |
784124 KB |
Output is correct |
2 |
Incorrect |
220 ms |
784132 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
221 ms |
784464 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
221 ms |
784464 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
355 ms |
784124 KB |
Output is correct |
2 |
Incorrect |
220 ms |
784132 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |