//Sylwia Sapkowska
#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
using namespace std;
void __print(int x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef LOCAL
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif
#define int long long
typedef pair<int, int> T;
const int oo = 1e18, oo2 = 1e9+7, K = 30;
const int mod = 998244353;
void solve(){
int n, t, m;
cin >> n >> t >> m;
vector<vector<int>>g(n+1);
for (int i = 1; i<n; i++){
int a, b; cin >> a >> b;
g[a].emplace_back(b);
g[b].emplace_back(a);
}
vector<int>dp(n+1), par(n+1);
function<void(int, int)>dfs = [&](int v, int pa){
par[v] = pa;
int mx = 0, mx2 = 0;
for (auto x: g[v]){
if (x == pa) continue;
dfs(x, v);
if (dp[x] >= mx){
mx2 = mx;
mx = dp[x];
} else if (dp[x] >= mx2) {
mx2 = dp[x];
}
}
dp[v] = (int)g[v].size() - (v == t ? 0 : 1) + mx2;
};
dfs(t, t);
debug(dp);
int v = m;
int ans = 0;
while (1){
ans = max(ans, dp[v]);
if (v == par[v]) break;
v = par[v];
}
cout << ans << "\n";
}
int32_t main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t = 1;
// cin >> t;
while (t--) solve();
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
308 ms |
91852 KB |
Output is correct |
2 |
Correct |
262 ms |
82880 KB |
Output is correct |
3 |
Correct |
671 ms |
90048 KB |
Output is correct |
4 |
Correct |
307 ms |
45040 KB |
Output is correct |
5 |
Correct |
691 ms |
90040 KB |
Output is correct |
6 |
Correct |
678 ms |
90060 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |