// Remember...
#include<bits/stdc++.h>
#define F first
#define S second
#define PB push_back
#define sz(s) int((s).size())
#define bit(n,k) (((n)>>(k))&1)
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
const int maxn=1e6+10,mod=1e9+7;
const ll inf=1e18;
vector<int> v[maxn];
int dp[maxn];
void dfs(int u,int par){
int id=-1, cnt=0;
for(int y:v[u]){
if(y!=par){
cnt++;
dfs(y,u);
if(id==-1 || dp[id]<dp[y])
id=y;
}
}
for(int y:v[u]){
if(y!=par && y!=id)
dp[u]=max(dp[u], dp[y]);
}
dp[u]+=cnt;
}
int main(){
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie();
int n,m,t; cin>>n>>m>>t;
for(int i=0;i<n-1;i++){
int a,b; cin>>a>>b;
v[a].PB(b);
v[b].PB(a);
}
dfs(m,t);
return cout<<dp[m]<<endl,0;
}
// Deathly mistakes:
// * Read the problem carefully.
// * Check maxn.
// * Overflows.
// #pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
25 ms |
23804 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
399 ms |
55160 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
25 ms |
23804 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
25 ms |
23804 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |