#include<bits/stdc++.h>
#define ll long long
#define f first
#define s second
#define pb push_back
using namespace std;
ll ch[500005],dp[500005],ans,n;
vector<ll>v[500005];
void go(ll x,ll par){
ch[x] = 1;
dp[x] = 0;
for(int i=0; i<v[x].size(); i++){
if(v[x][i] != par){
go(v[x][i] , x);
ch[x] += ch[v[x][i]];
dp[x] = max(dp[x] , dp[v[x][i]]);
}
}
for(int i=0; i<v[x].size(); i++){
if(v[x][i] != par){
dp[x] = max(dp[x] , min(ch[v[x][i]] , ch[x] - ch[v[x][i]]));
}
}
ll mn = min(dp[x] , n - ch[x]);
ll mx = max(ch[x] - dp[x] , n - ch[x]);
//ans = min(ans , mx - mn);
}
void ze(ll x,ll par,ll zed){
ll mn = min(zed , ch[x]);
ll mx = max(n - ch[x] - zed , ch[x]);
ans = min(ans , mx - mn);
multiset<ll>st,st1;
st.insert(zed);
for(int i=0; i<v[x].size(); i++){
if(v[x][i] == par)continue;
st.insert(dp[v[x][i]]);
}
for(int i=0; i<v[x].size(); i++){
if(v[x][i] != par){
ll Z = max(zed , min(n - ch[x] , ch[x] - ch[v[x][i]]));
for(int j=0; j<v[x].size(); j++){
if(v[x][j] != par && i != j){
Z = max(Z , dp[v[x][j]]);
Z = max(Z , min(n - ch[v[x][i]] - ch[v[x][j]] , ch[v[x][j]]));
}
}
//st.erase(st.find(ch[v[x][i]]));
//st.erase(st.find(dp[v[x][i]]));
ze(v[x][i] , x , Z);
//st.insert(ch[v[x][i]]);
//st.insert(dp[v[x][i]]);
}
}
}
int main(){
ios::sync_with_stdio(false);
cin >> n;
for(int i=1; i<n; i++){
ll x,y;
cin >> x >> y;
v[x].pb(y);
v[y].pb(x);
}
ans = n;
go(1 , 0);
ze(1 , 0 , 0);
cout << ans << '\n';
return 0;
}
Compilation message
papricice.cpp: In function 'void go(long long int, long long int)':
papricice.cpp:12:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
12 | for(int i=0; i<v[x].size(); i++){
| ~^~~~~~~~~~~~
papricice.cpp:19:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
19 | for(int i=0; i<v[x].size(); i++){
| ~^~~~~~~~~~~~
papricice.cpp:24:8: warning: unused variable 'mn' [-Wunused-variable]
24 | ll mn = min(dp[x] , n - ch[x]);
| ^~
papricice.cpp:25:8: warning: unused variable 'mx' [-Wunused-variable]
25 | ll mx = max(ch[x] - dp[x] , n - ch[x]);
| ^~
papricice.cpp: In function 'void ze(long long int, long long int, long long int)':
papricice.cpp:34:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
34 | for(int i=0; i<v[x].size(); i++){
| ~^~~~~~~~~~~~
papricice.cpp:38:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
38 | for(int i=0; i<v[x].size(); i++){
| ~^~~~~~~~~~~~
papricice.cpp:41:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
41 | for(int j=0; j<v[x].size(); j++){
| ~^~~~~~~~~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
10 ms |
12140 KB |
Output is correct |
| 2 |
Incorrect |
9 ms |
12140 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
10 ms |
12140 KB |
Output is correct |
| 2 |
Incorrect |
9 ms |
12140 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
10 ms |
12140 KB |
Output is correct |
| 2 |
Incorrect |
9 ms |
12140 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
