// oooo
/*
har chi delet mikhad bebar ~
gitar o ba khodet nabar! ~
;Amoo_Hasan;
*/
#include<bits/stdc++.h>
//#pragma GCC optimize("O3,no-stack-protector,unroll-loops")
//#pragma GCC target("avx2,fma")
using namespace std;
typedef long long ll;
typedef long double ld;
#define Sz(x) int((x).size())
#define All(x) (x).begin(), (x).end()
#define wtf(x) cout<<#x <<" : " <<x <<endl
constexpr ll inf = 1e18, N = 1e6 + 10, mod = 1e9 + 7, pr = 1000696969;
int n, t, m, total;
bool mark[N];
ll dp[N], par[N], ps[N];
vector<int> adj[N];
void dfs(int x, int p = 0) {
par[x] = p;
if(x != t) {
ps[x] = ps[p] + max(0, Sz(adj[x]) - 2);
}
int tim = 0;
vector<ll> vc;
for(auto j : adj[x]) {
if(j == p) continue;
tim++;
dfs(j, x);
vc.push_back(dp[j]);
}
sort(All(vc), greater<int>());
if(tim == 0) {
dp[x] = 0;
return;
}
if(tim == 1) {
dp[x] = 1;
return;
}
dp[x] = tim;
dp[x] += vc[1];
}
ll solve(int x) {
vector<ll> vc;
for(auto j : adj[x]) {
if(mark[j] || j == par[x]) continue;
vc.push_back(dp[j]);
}
sort(All(vc), greater<int>());
ll cnt = ps[par[x]];
cnt += Sz(vc);
if(Sz(vc) >= total + 1) cnt += vc[total];
return cnt;
}
int main() {
ios :: sync_with_stdio(0), cin.tie(0);
cin >>n >>t >>m;
for(int i = 0; i < n - 1; i++) {
int u, v; cin >>u >>v;
adj[u].push_back(v), adj[v].push_back(u);
}
dfs(t);
if(t == m) {
cout<<0;
return 0;
}
total = 1;
ll ans = solve(m);
mark[m] = 1;
int x = par[m];
while(x != t && x != 0) {
total++;
ans = max(ans, solve(x));
mark[x] = 1;
x = par[x];
}
cout<<ans;
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
12 ms |
23704 KB |
Output is correct |
2 |
Correct |
14 ms |
23736 KB |
Output is correct |
3 |
Correct |
12 ms |
23764 KB |
Output is correct |
4 |
Correct |
16 ms |
23828 KB |
Output is correct |
5 |
Correct |
13 ms |
23832 KB |
Output is correct |
6 |
Correct |
13 ms |
23820 KB |
Output is correct |
7 |
Correct |
16 ms |
23916 KB |
Output is correct |
8 |
Correct |
12 ms |
23724 KB |
Output is correct |
9 |
Correct |
12 ms |
23764 KB |
Output is correct |
10 |
Correct |
12 ms |
23936 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
335 ms |
78556 KB |
Output is correct |
2 |
Correct |
277 ms |
73108 KB |
Output is correct |
3 |
Correct |
749 ms |
79684 KB |
Output is correct |
4 |
Correct |
367 ms |
51764 KB |
Output is correct |
5 |
Correct |
769 ms |
79692 KB |
Output is correct |
6 |
Correct |
804 ms |
79684 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
12 ms |
23704 KB |
Output is correct |
2 |
Correct |
14 ms |
23736 KB |
Output is correct |
3 |
Correct |
12 ms |
23764 KB |
Output is correct |
4 |
Correct |
16 ms |
23828 KB |
Output is correct |
5 |
Correct |
13 ms |
23832 KB |
Output is correct |
6 |
Correct |
13 ms |
23820 KB |
Output is correct |
7 |
Correct |
16 ms |
23916 KB |
Output is correct |
8 |
Correct |
12 ms |
23724 KB |
Output is correct |
9 |
Correct |
12 ms |
23764 KB |
Output is correct |
10 |
Correct |
12 ms |
23936 KB |
Output is correct |
11 |
Incorrect |
13 ms |
23764 KB |
Output isn't correct |
12 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
12 ms |
23704 KB |
Output is correct |
2 |
Correct |
14 ms |
23736 KB |
Output is correct |
3 |
Correct |
12 ms |
23764 KB |
Output is correct |
4 |
Correct |
16 ms |
23828 KB |
Output is correct |
5 |
Correct |
13 ms |
23832 KB |
Output is correct |
6 |
Correct |
13 ms |
23820 KB |
Output is correct |
7 |
Correct |
16 ms |
23916 KB |
Output is correct |
8 |
Correct |
12 ms |
23724 KB |
Output is correct |
9 |
Correct |
12 ms |
23764 KB |
Output is correct |
10 |
Correct |
12 ms |
23936 KB |
Output is correct |
11 |
Correct |
335 ms |
78556 KB |
Output is correct |
12 |
Correct |
277 ms |
73108 KB |
Output is correct |
13 |
Correct |
749 ms |
79684 KB |
Output is correct |
14 |
Correct |
367 ms |
51764 KB |
Output is correct |
15 |
Correct |
769 ms |
79692 KB |
Output is correct |
16 |
Correct |
804 ms |
79684 KB |
Output is correct |
17 |
Incorrect |
13 ms |
23764 KB |
Output isn't correct |
18 |
Halted |
0 ms |
0 KB |
- |