#include <bits/stdc++.h>
#define pb push_back
#define F first
#define S second
using namespace std;
typedef long long ll;
typedef string str;
const ll Mod = 1e9 + 7;
const int Maxn = 1e6 + 100;
vector<ll> G[Maxn];
ll dp[Maxn];
ll t, m;
bool DFS(ll u, ll p){
bool res = (u == m);
ll cnt = 0;
ll mx = 0;
ll mx2 = 0;
for(auto adj : G[u]){
if(adj == p) continue;
res |= DFS(adj, u);
cnt ++;
if(dp[adj] > mx){
mx2 = mx;
mx = dp[adj];
} else mx2 = max(mx2, dp[adj]);
}
dp[u] = cnt + mx2;
return res;
}
int main(){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
ll n;
cin >> n >> t >> m;
ll u, v;
for(int i = 1; i < n; i++){
cin >> u >> v;
G[u].pb(v);
G[v].pb(u);
}
DFS(t, -1);
cout << dp[m] << '\n';
return 0;
}
/*
5 1 2
1 2
2 3
2 4
3 5
*/
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
24 ms |
23928 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
460 ms |
81836 KB |
Output is correct |
2 |
Correct |
407 ms |
78120 KB |
Output is correct |
3 |
Correct |
980 ms |
82304 KB |
Output is correct |
4 |
Correct |
497 ms |
52932 KB |
Output is correct |
5 |
Correct |
990 ms |
82504 KB |
Output is correct |
6 |
Correct |
1008 ms |
82364 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
24 ms |
23928 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
24 ms |
23928 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |