#include "race.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll N=2e5+10;
struct edge{
ll to,nxt,w;
}ln[N*2];
ll idx[N],topln;
void add_edge(ll u,ll v,ll w){
ln[++topln]=(edge){v,idx[u],w},idx[u]=topln;
ln[++topln]=(edge){u,idx[v],w},idx[v]=topln;
}
ll k;
ll S,rt,rtmx,vis[N],siz[N];
void init(ll x){S=x,rt=0,rtmx=N;}
void findrt(ll x,ll fa){
ll mx=0; siz[x]=1;
for(ll i=idx[x];i;i=ln[i].nxt){
if(ln[i].to==fa || vis[ln[i].to]) continue;
findrt(ln[i].to,x);
siz[x]+=siz[ln[i].to];
mx=max(mx,siz[ln[i].to]);
}
mx=max(mx,S-siz[x]);
if(mx<rtmx) mx=rtmx,rt=x;
}
const ll K=1e6+10;
ll ans=N,dis[N],top=0,cnt[K];
struct node{
ll w,d;
}mrk[N];
ll mrk2[N];
void Count(ll x,ll fa,ll d){
if(dis[x]>k || d>=ans) return;
mrk[++top]=(node){dis[x],d};
for(ll i=idx[x];i;i=ln[i].nxt){
if(ln[i].to==fa || vis[ln[i].to]) continue;
dis[ln[i].to]=dis[x]+ln[i].w;
Count(ln[i].to,x,d+1);
}
}
void solve(ll x){
ll top2=0;
cnt[0]=0;
for(ll i=idx[x];i;i=ln[i].nxt){
if(vis[ln[i].to]) continue;
top=0;
dis[ln[i].to]=ln[i].w,Count(ln[i].to,x,1);
for(ll j=1;j<=top;j++)
if(cnt[k-mrk[j].w]!=cnt[K-1]){
ans=min(ans,mrk[j].d+cnt[k-mrk[j].w]);
}
for(ll j=1;j<=top;j++){
cnt[mrk[j].w]=min(cnt[mrk[j].w],mrk[j].d);
mrk2[++top2]=mrk[j].w;
}
}
for(ll i=1;i<=top2;i++) cnt[mrk2[i]]=cnt[K-1];
}
void dfs(ll x){
vis[x]=1;
solve(x);
for(ll i=idx[x];i;i=ln[i].nxt){
if(vis[ln[i].to]) continue;
init(siz[ln[i].to]),findrt(ln[i].to,0);
dfs(rt);
}
}
int best_path(int N, int K, int H[][2], int L[])
{
memset(cnt,127,sizeof(cnt));
ll n=N;
k=K;
for(ll i=1;i<n;i++){
ll u=H[i-1][0]+1,v=H[i-1][1]+1,w=L[i-1];
add_edge(u,v,w);
}
init(n),findrt(1,0);
dfs(1);
if(ans==N) return -1;
else return ans;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
8140 KB |
Output is correct |
2 |
Correct |
5 ms |
8108 KB |
Output is correct |
3 |
Incorrect |
5 ms |
8140 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
8140 KB |
Output is correct |
2 |
Correct |
5 ms |
8108 KB |
Output is correct |
3 |
Incorrect |
5 ms |
8140 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
8140 KB |
Output is correct |
2 |
Correct |
5 ms |
8108 KB |
Output is correct |
3 |
Incorrect |
5 ms |
8140 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
8140 KB |
Output is correct |
2 |
Correct |
5 ms |
8108 KB |
Output is correct |
3 |
Incorrect |
5 ms |
8140 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |