#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
#define ONLINE_JUDGE
void solve() {
int n, t, m;
cin >> n >> t >> m;
if(m == t) {
cout << 0 << "\n";
return;
}
vector <int> adj[n +1];
for(int i = 1; i <= n -1; i++) {
int u, v;
cin >> u >> v;
adj[u].emplace_back(v);
adj[v].emplace_back(u);
}
function <int(int, int)> dfs = [&](int node, int par) -> int {
//cerr << node << " " << par << "\n";
vector <int> chills;
for(int child : adj[node]) {
if(child == par) {
continue;
}
chills.emplace_back(dfs(child, node) +2);
}
sort(chills.begin(), chills.end(), greater <> ());
if(int(chills.size()) <= 1) {
return 0;
}
//cerr << node << " " << par << " :: " << chills[1] << " " << int(chills.size()) << "\n";
return chills[1] + int(chills.size()) -1;
};
cout << dfs(m, t) +1;
return;
}
signed main() {
#ifndef ONLINE_JUDGE
freopen(".in", "r", stdin);
freopen(".out", "w", stdout);
#endif
ios_base::sync_with_stdio(false);
cin.tie(NULL); cout.tie(NULL);
int t = 1; //cin >> t;
for(int i = 1; i <= t; i++) {
solve();
}
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
244 ms |
55084 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |