| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1304539 | h1drogen | Race (IOI11_race) | C++20 | 0 ms | 0 KiB |
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define ll long long
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define f first
#define s second
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define imp cout<<-1<<"\n"
#define pb push_back
#define pii pair<int,int>
#define piii pair<int,pair<int,int>>
#define ls v<<1
#define rs v<<1|1
#define fast ios::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#define ptree tree *
const int mod=1e9+7;
const int INF = 1e18;
const int N=1e5+50;
const int logn=18;
vector<int>dp[105];
vector<int>suf[105];
vector<vector<pii>>g;
int ans=INT_MAX;
void dfs(int v,int p){
dp[0][v]=0;
for(auto k:g[v]){
if(k.f!=p){
for(int i=0;i<=100-k.s;i++){
dp[i+k.s][k.f]=min(dp[i+k.s][k.f],dp[i][v]+1);
}
dfs(k.f,v);
for(int i=0;i<=100-k.s;i++){
dp[i+k.s][v]=min(dp[i+k.s][v],suf[i][k.f]+1);
suf[i+k.s][v]=min(suf[i+k.s][v],suf[i][k.f]+1);
}
}
}
suf[0][v]=0;
}
void solve(){
int n,k;
cin>>n>>k;
int a,b,c;
g.resize(n+1);
for(int i=0;i<n-1;i++){
cin>>a>>b>>c;
g[a].pb({b,c});
g[b].pb({a,c});
}
for(int i=0;i<=100;i++){
dp[i].resize(n+1);
suf[i].resize(n+1);
for(int j=0;j<n;j++){
dp[i][j]=INT_MAX;
suf[i][j]=INT_MAX;
}
}
dfs(1,-1);
for(int i=0;i<n;i++){
ans=min(dp[k][i],ans);
// cout<<dp[k][i]<<" ";
}
cout<<ans<<"\n";
}
signed main(){
fast;
int t=1;
// cin>>t;
while(t--){
solve();
}
return 0;
}