#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define endl '\n'
#define MASK(i) (1LL << (i))
#define ull unsigned long long
#define ld long double
#define pb push_back
#define all(x) (x).begin() , (x).end()
#define BIT(x , i) ((x >> (i)) & 1)
#define TASK "task"
#define sz(s) (int) (s).size()
using namespace std;
const int mxN = 1e6 + 227;
const int inf = 1e9 + 277;
const int mod = 1e9 + 7;
const ll infll = 1e18 + 7;
const int base = 200;
const int LOG = 20;
template <typename T1, typename T2> bool minimize(T1 &a, T2 b) {
if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b) {
if (a < b) {a = b; return true;} return false;
}
int n;
int t;
int m;
int dp[mxN];
vector<int> adj[mxN];
void dfs(int u, int par)
{
vector<int> val;
for(int v : adj[u]) {
if(v == par || v == t) continue;
dfs(v, u);
val.pb(dp[v]);
}
sort(all(val));
reverse(all(val));
if(sz(val) <= 1) dp[u] = 0;
else dp[u] = val[1] + 1;
}
void solve()
{
cin >> n >> t >> m;
for(int i = 1; i < n; i++) {
int u, v;
cin >> u >> v;
adj[u].pb(v);
adj[v].pb(u);
}
dfs(m, -1);
cout << dp[m] * 2 << endl;
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
//freopen(TASK".in" , "r" , stdin);
//freopen(TASK".out" , "w" , stdout);
int tc = 1;
// cin >> tc;
while(tc--) {
solve();
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
12 ms |
23820 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
303 ms |
72312 KB |
Output is correct |
2 |
Correct |
278 ms |
67432 KB |
Output is correct |
3 |
Incorrect |
744 ms |
73292 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
12 ms |
23820 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
12 ms |
23820 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |