#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
/*const int MOD = ;
inline int lgput(int a, int b) {
int ans = 1;
while(b > 0) {
if(b & 1) ans = (1LL * ans * a) % MOD;
b >>= 1;
a = (1LL * a * a) % MOD;
}
return ans;
}
inline void mod(int &x) {
if(x >= MOD)
x -= MOD;
}
inline void add(int &x, int y) {
x += y;
mod(x);
}
inline void sub(int &x, int y) {
x += MOD - y;
mod(x);
}
inline void mul(int &x, int y) {
x = (1LL * x * y) % MOD;
}
inline int inv(int x) {
return lgput(x, MOD - 2);
}*/
/*int fact[], invfact[];
inline void prec(int n) {
fact[0] = 1;
for(int i = 1; i <= n; i++) {
fact[i] = (1LL * fact[i - 1] * i) % MOD;
}
invfact[n] = lgput(fact[n], MOD - 2);
for(int i = n - 1; i >= 0; i--) {
invfact[i] = (1LL * invfact[i + 1] * (i + 1)) % MOD;
}
}
inline int comb(int n, int k) {
if(n < k) return 0;
return (1LL * fact[n] * (1LL * invfact[k] * invfact[n - k] % MOD)) % MOD;
}*/
using namespace std;
const int MAXN = (int) 1e6;
vector <int> g[MAXN + 1];
int father[MAXN + 1], lvl[MAXN + 1];
void dfs(int nod, int par) {
father[nod] = par;
lvl[nod] = lvl[par] + 1;
for(auto it : g[nod]) {
if(it != par) {
dfs(it, nod);
}
}
}
int dp[MAXN + 1];
inline void combine(pair <int, int> &mx, int cur) {
if(mx.first < cur) {
mx.second = mx.first;
mx.first = cur;
}
else if(mx.second < cur) {
mx.second = cur;
}
}
void go(int nod, int par, int sum) {
int sz = (int) g[nod].size();
if(sz == 0) {
dp[nod] = sum;
return ;
}
if(sz == 1) {
dp[nod] = 1 + sum;
return ;
}
pair <int, int> mx = {0, 0};
for(auto it : g[nod]) {
if(it != par) {
go(it, nod, sum + sz - 1);
combine(mx, dp[it]);
}
}
dp[nod] = mx.second;
}
int main() {
#if 0
ifstream cin("A.in");
ofstream cout("A.out");
#endif
int i, n, t, m;
ios::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
cin >> n >> t >> m;
for(i = 1; i < n; i++) {
int x, y;
cin >> x >> y;
g[x].push_back(y);
g[y].push_back(x);
}
dfs(t, 0);
int nod = m, dst = 1;
go(m, father[m], 0);
vector < pair <int, int> > nodes; nodes.push_back({m, 0});
while(father[nod] != t) {
dst++;
for(auto it : g[father[nod]]) {
if(it != nod && lvl[it] == lvl[nod]) {
go(it, father[it], 0);
nodes.push_back({it, dst});
}
}
nod = father[nod];
}
auto check = [&](int X) {
int cnt = 0;
for(auto it : nodes) {
if(it.first + cnt > X) {
cnt++;
}
if(cnt > it.second) {
return 0;
}
}
return 1;
};
int res = -1;
for(int step = 1 << 20; step; step >>= 1) {
if(check(res + step) == 0) {
res += step;
}
}
cout << res + 1;
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
23 ms |
23800 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
443 ms |
80356 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
23 ms |
23800 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
23 ms |
23800 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
