#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define ll long long
const int MAX=1e5+10, L=19;
const ll MAXV=1e16;
int n, s, q, e, a[MAX], b[MAX], w;
bool sk[MAX];
vector<pair<int,int>>g[MAX];
int czas, pre[MAX], maxiPre[MAX];
ll naj[MAX], gle[MAX], gle2[MAX];
pair<int,ll>jump[MAX][L];
pair<int,int> o[MAX];
void dfs(int v, int oj){
pre[v]=++czas;
naj[v]=MAXV;
if(sk[v])
naj[v]=0;
for(auto s:g[v]){
if(s.fi!=oj){
gle[s.fi]=gle[v]+1;
gle2[s.fi]=gle2[v]+s.se;
o[s.fi]={v, s.se};
dfs(s.fi, v);
naj[v]=min(naj[v], naj[s.fi]+(ll)s.se);
}
}
maxiPre[v]=czas;
}
int main(){
/* ios_base::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
*/ cin>>n>>s>>q>>e;
for(int i=1; i<=n-1; i++){
cin>>a[i]>>b[i]>>w;
g[a[i]].pb({b[i], w}), g[b[i]].pb({a[i], w});
}
for(int i=1; i<=s; i++){
int c;
cin>>c;
sk[c]=true;
}
dfs(e, e);
for(int i=1; i<=n; i++)
jump[i][0]={o[i].fi, min(naj[i], o[i].se+naj[o[i].fi])};
for(int i=1; i<L; i++){
for(int j=1; j<=n; j++){
jump[j][i].fi=jump[jump[j][i-1].fi][i-1].fi;
jump[j][i].se=min(jump[j][i-1].se, jump[jump[j][i-1].fi][i-1].se+gle2[j]-gle2[jump[j][i-1].fi]);
}
}
while(q--){
int x, y;
cin>>x>>y;
int u1=a[x], u2=b[x];
if(pre[u1]>pre[u2])
swap(u1, u2);
if(pre[u2]>pre[y] || maxiPre[u2]<pre[y]){
cout<<"escaped\n";
continue;
}
if(naj[u2]==MAXV){
cout<<"oo\n";
continue;
}
int doU2=gle[y]-gle[u2];
//cout<<doU2<<"\n";
int y1=y, licz=0;
ll odl=naj[y], akt=0;
while(doU2){
if(doU2%2){
//cout<<y1<<" "<<licz<<" "<<jump[y1][licz].se<<"\n";
odl=min(odl, akt+jump[y1][licz].se);
akt+=gle2[y1]-gle2[jump[y1][licz].fi];
y1=jump[y1][licz].fi;
}
doU2/=2, licz++;
}
cout<<odl<<"\n";
}
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
18 ms |
2776 KB |
Output is correct |
2 |
Correct |
23 ms |
2764 KB |
Output is correct |
3 |
Correct |
20 ms |
2776 KB |
Output is correct |
4 |
Correct |
18 ms |
2764 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
18 ms |
2776 KB |
Output is correct |
2 |
Correct |
23 ms |
2764 KB |
Output is correct |
3 |
Correct |
20 ms |
2776 KB |
Output is correct |
4 |
Correct |
18 ms |
2764 KB |
Output is correct |
5 |
Correct |
5 ms |
3020 KB |
Output is correct |
6 |
Correct |
4 ms |
3012 KB |
Output is correct |
7 |
Correct |
5 ms |
3020 KB |
Output is correct |
8 |
Correct |
4 ms |
3020 KB |
Output is correct |
9 |
Correct |
5 ms |
3020 KB |
Output is correct |
10 |
Correct |
5 ms |
3020 KB |
Output is correct |
11 |
Correct |
4 ms |
3020 KB |
Output is correct |
12 |
Correct |
5 ms |
3020 KB |
Output is correct |
13 |
Correct |
5 ms |
3020 KB |
Output is correct |
14 |
Correct |
4 ms |
3020 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
375 ms |
41664 KB |
Output is correct |
2 |
Correct |
377 ms |
41336 KB |
Output is correct |
3 |
Correct |
414 ms |
41460 KB |
Output is correct |
4 |
Correct |
419 ms |
43056 KB |
Output is correct |
5 |
Correct |
387 ms |
43192 KB |
Output is correct |
6 |
Correct |
430 ms |
45076 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
18 ms |
2776 KB |
Output is correct |
2 |
Correct |
23 ms |
2764 KB |
Output is correct |
3 |
Correct |
20 ms |
2776 KB |
Output is correct |
4 |
Correct |
18 ms |
2764 KB |
Output is correct |
5 |
Correct |
5 ms |
3020 KB |
Output is correct |
6 |
Correct |
4 ms |
3012 KB |
Output is correct |
7 |
Correct |
5 ms |
3020 KB |
Output is correct |
8 |
Correct |
4 ms |
3020 KB |
Output is correct |
9 |
Correct |
5 ms |
3020 KB |
Output is correct |
10 |
Correct |
5 ms |
3020 KB |
Output is correct |
11 |
Correct |
4 ms |
3020 KB |
Output is correct |
12 |
Correct |
5 ms |
3020 KB |
Output is correct |
13 |
Correct |
5 ms |
3020 KB |
Output is correct |
14 |
Correct |
4 ms |
3020 KB |
Output is correct |
15 |
Correct |
375 ms |
41664 KB |
Output is correct |
16 |
Correct |
377 ms |
41336 KB |
Output is correct |
17 |
Correct |
414 ms |
41460 KB |
Output is correct |
18 |
Correct |
419 ms |
43056 KB |
Output is correct |
19 |
Correct |
387 ms |
43192 KB |
Output is correct |
20 |
Correct |
430 ms |
45076 KB |
Output is correct |
21 |
Correct |
343 ms |
41816 KB |
Output is correct |
22 |
Correct |
345 ms |
41440 KB |
Output is correct |
23 |
Correct |
337 ms |
41404 KB |
Output is correct |
24 |
Correct |
415 ms |
43228 KB |
Output is correct |
25 |
Correct |
380 ms |
46172 KB |
Output is correct |
26 |
Correct |
334 ms |
41724 KB |
Output is correct |
27 |
Correct |
379 ms |
41344 KB |
Output is correct |
28 |
Correct |
342 ms |
41284 KB |
Output is correct |
29 |
Correct |
361 ms |
42676 KB |
Output is correct |
30 |
Correct |
390 ms |
44136 KB |
Output is correct |
31 |
Correct |
335 ms |
41852 KB |
Output is correct |
32 |
Correct |
391 ms |
41516 KB |
Output is correct |
33 |
Correct |
345 ms |
41628 KB |
Output is correct |
34 |
Correct |
402 ms |
43216 KB |
Output is correct |
35 |
Correct |
388 ms |
46020 KB |
Output is correct |
36 |
Correct |
352 ms |
43928 KB |
Output is correct |