#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) a.begin(),a.end()
const int mxN=(int)1e4+10;
const int LINF = (int)1e9;
int n, k, s, sub[mxN];
vector<pair<int,int>> adj[mxN];
int dp[mxN][mxN][2], dp2[mxN][mxN][2];
int findSize(int s, int p){
sub[s]=1;
for(auto [u,w] : adj[s])
if(u!=p) sub[s]+=findSize(u,s);
return sub[s];
}
void dfs(int s, int p){
vector<pair<int,int>> v; v.clear();
for(auto [u,w] : adj[s])
if(u!=p) dfs(u,s), v.pb({u,w});
dp[s][1][0]=dp[s][1][1]=0;
if(!sz(v)) return;
for(int i = 0; i <= sz(v); i++)
for(int j = 0; j <= k; j++)
dp2[i][j][0]=dp2[i][j][1]=LINF;
dp2[0][0][0] = dp2[0][0][1] = 0; int tot = 1;
for(int i = 1; i <= sz(v); i++){
auto u = v[i-1].fi;
for(int j = 0; j <= k; j++){
for(int x = 0; x < 2; x++){
dp2[i][j][x] = min(dp2[i][j][x],dp2[i-1][j][x]);
for(int l = 1; l <= j; l++){
dp2[i][j][x] = min(dp2[i][j][x], dp2[i-1][j-l][x]+dp[u][l][1]+2*v[i-1].se);
if(!x)dp2[i][j][x] = min(dp2[i][j][x], dp2[i-1][j-l][1]+dp[u][l][0]+v[i-1].se);
}
}
}
tot+=sub[u];
}
for(int i = 2; i <= k; i++)
for(int j = 0; j < 2; j++)
dp[s][i][j] = min(dp[s][i][j],dp2[sz(v)][i-1][j]);
}
int32_t main()
{
ios_base::sync_with_stdio(false); cin.tie(0);
cin >> n >> k >> s;
for(int i = 0; i < mxN; i++)
for(int j = 0; j < mxN; j++)
dp[i][j][0]=dp[i][j][1]=LINF;
for(int i = 1; i < n; i++){
int a, b, c; cin >> a >> b >> c;
adj[a].pb({b,c}), adj[b].pb({a,c});
}
findSize(s,-1); dfs(s,-1); cout << dp[s][k][0];
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
335 ms |
784972 KB |
Output is correct |
2 |
Correct |
343 ms |
784796 KB |
Output is correct |
3 |
Correct |
344 ms |
784972 KB |
Output is correct |
4 |
Correct |
341 ms |
784988 KB |
Output is correct |
5 |
Correct |
328 ms |
784940 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
749 ms |
785396 KB |
Output is correct |
2 |
Correct |
758 ms |
785348 KB |
Output is correct |
3 |
Correct |
791 ms |
785980 KB |
Output is correct |
4 |
Correct |
757 ms |
785684 KB |
Output is correct |
5 |
Correct |
739 ms |
785360 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
749 ms |
785396 KB |
Output is correct |
2 |
Correct |
758 ms |
785348 KB |
Output is correct |
3 |
Correct |
791 ms |
785980 KB |
Output is correct |
4 |
Correct |
757 ms |
785684 KB |
Output is correct |
5 |
Correct |
739 ms |
785360 KB |
Output is correct |
6 |
Correct |
752 ms |
785376 KB |
Output is correct |
7 |
Correct |
769 ms |
785740 KB |
Output is correct |
8 |
Correct |
802 ms |
835000 KB |
Output is correct |
9 |
Correct |
828 ms |
795440 KB |
Output is correct |
10 |
Correct |
762 ms |
785892 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
335 ms |
784972 KB |
Output is correct |
2 |
Correct |
343 ms |
784796 KB |
Output is correct |
3 |
Correct |
344 ms |
784972 KB |
Output is correct |
4 |
Correct |
341 ms |
784988 KB |
Output is correct |
5 |
Correct |
328 ms |
784940 KB |
Output is correct |
6 |
Correct |
749 ms |
785396 KB |
Output is correct |
7 |
Correct |
758 ms |
785348 KB |
Output is correct |
8 |
Correct |
791 ms |
785980 KB |
Output is correct |
9 |
Correct |
757 ms |
785684 KB |
Output is correct |
10 |
Correct |
739 ms |
785360 KB |
Output is correct |
11 |
Correct |
752 ms |
785376 KB |
Output is correct |
12 |
Correct |
769 ms |
785740 KB |
Output is correct |
13 |
Correct |
802 ms |
835000 KB |
Output is correct |
14 |
Correct |
828 ms |
795440 KB |
Output is correct |
15 |
Correct |
762 ms |
785892 KB |
Output is correct |
16 |
Execution timed out |
3083 ms |
785368 KB |
Time limit exceeded |
17 |
Halted |
0 ms |
0 KB |
- |