#include <bits/stdc++.h>
#define el '\n'
#define fu(i, a, b) for (long long i = a; i <= b; ++i)
#define fd(i, a, b) for (long long i = a; i >= b; --i)
#define ff first
#define ss second
#define all(v) v.begin(), v.end()
#define sz(v) (ll)v.size()
#define mask(i) (1LL << i)
#define bit(x, i) ((x) >> (i) & 1)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll Rand(ll l, ll r) {
return uniform_int_distribution<ll> (l, r) (rng);
}
ll last(ll msk) {return msk & (-msk);}
ll pop_cnt(ll msk) {return __builtin_popcountll(msk);}
ll ctz(ll msk) {return __builtin_ctzll(msk);}
ll lg(ll msk) {return 63 - __builtin_clzll(msk);}
template<class T1, class T2>
bool maximize(T1 &a, T2 b) {
if (a < b) {
a = b;
return true;
}
return false;
}
template<class T1, class T2>
bool minimize(T1 &a, T2 b) {
if (a > b) {
a = b;
return true;
}
return false;
}
template<class T>
void print(T &a, string sep = " ", string stop = "\n") {
for (auto x : a) cout << x << sep;
cout << stop;
}
template<class T>
void compress(vector<T> &v) {
sort(all(v));
v.resize(unique(all(v)) - v.begin());
}
const long long N = 1e6 + 27, base = 311, inf = 2e18, mod = 1e9 + 19972207;
ll n, t, m, timer;
ll a[N], f[N];
vector<ll> adj[N];
void update(ll &a, ll &b, ll c) {
if (a < c) {
b = a;
a = c;
}
else maximize(b, c);
}
void dfs(ll u, ll p) {
ll fi = 0, se = 0;
for (ll v : adj[u]) {
if (v == p || v == t) continue;
dfs(v, u);
update(fi, se, f[v]);
}
if (sz(adj[u]) > 1) f[u]++;
if (se) f[u] += se + 1;
}
signed main() {
// freopen("brentford40mu.inp", "r", stdin);
// freopen("brentford40mu.out", "w", stdout);
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n >> t >> m;
if (t == m) return cout << 0, 0;
fu(i, 2, n) {
ll u, v;
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
dfs(m, 0);
cout << f[m];
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
3 ms |
25176 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
149 ms |
80100 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
3 ms |
25176 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
3 ms |
25176 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |