#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
const int N = 2e5 + 10;
vector<int> nei[N];
int par[N];
int Mx1[N];
int Mx2[N];
void Dfs(int u,int p = -1){
par[u] = p;
for (int i : nei[u]){
if (i==p)
continue;
Dfs(i,u);
int mx = Mx2[i] + 1;
if (mx>Mx1[u]){
Mx2[u] = Mx1[u];
Mx1[u] = mx;
}
else
Mx2[u] = max(Mx2[u],mx);
}
}
signed main(){
int n,t,m;
cin>>n>>t>>m;
for (int i=2;i<=n;i++){
int u,v;
cin>>u>>v;
nei[u].push_back(v);
nei[v].push_back(u);
}
Dfs(t);
// for (int i=1;i<=n;i++)
// cout<<Mx1[i]<<" "<<Mx2[i]<<endl;
int mx = 0;
int Mx = 1;
for (int i : nei[m]){
if (i==t)
continue;
if (Mx1[i] + 1>Mx){
mx = Mx;
Mx = Mx1[i] + 1;
}
else
mx = max(mx,Mx1[i] + 1);
}
int flag = true;
int block = 0;
for (int i : nei[m]){
if (i==t)
continue;
block++;
}
if (Mx==0){
cout<<0<<endl;
}
else if (mx == 0){
cout<<1<<endl;
}
else
cout<<block + mx - 1<<endl;
}
Compilation message
mousetrap.cpp: In function 'int main()':
mousetrap.cpp:57:6: warning: unused variable 'flag' [-Wunused-variable]
57 | int flag = true;
| ^~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
2 ms |
7260 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
107 ms |
22812 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
2 ms |
7260 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
2 ms |
7260 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |