#include <bits/stdc++.h>
using namespace std;
const int M = 2e5 + 1;
vector<int> nei[M];
int subt[M],ans,n;
set<int> se,se1;
void calc(int u,int p=0)
{
subt[u]=1;
for (int i:nei[u])
if (i!=p)
{
calc(i,u);
subt[u]+=subt[i];
}
}
void dfs(int u,int p=0)
{
int x=subt[u]+(n-subt[u])/2;
auto it=se.upper_bound(x);
int val=-1;
if (it!=se.end())
val=*it;
if (it!=se.begin())
{
it--;
if (val==-1 || val-x>x-*it)
val=*it;
}
if (val!=-1)
ans=min(max(max(abs(val-subt[u]*2),abs(n-val-subt[u])),abs(n-2*val+subt[u])),ans);
se.insert(subt[u]);
x=(n-subt[u])/2;
it=se1.upper_bound(x);
val=-1;
if (it!=se1.end())
val=*it;
if (it!=se1.begin())
{
it--;
if (val==-1 || val-x>x-*it)
val=*it;
}
if (val!=-1)
ans=min(ans,max(abs(n-2*val-subt[u]),max(abs(n-val-2*subt[u]),abs(val-subt[u]))));
for (int i:nei[u])
if (i!=p)
dfs(i,u);
se.erase(subt[u]);
se1.insert(subt[u]);
}
int main()
{
cin>>n;
ans=n;
for (int i=1;i<n;i++)
{
int u,v;
cin>>u>>v;
nei[u].push_back(v);
nei[v].push_back(u);
}
calc(1);
dfs(1);
cout<<ans<<endl;
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
5720 KB |
Output is correct |
2 |
Correct |
2 ms |
5724 KB |
Output is correct |
3 |
Correct |
2 ms |
5724 KB |
Output is correct |
4 |
Correct |
2 ms |
4956 KB |
Output is correct |
5 |
Correct |
2 ms |
4956 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
5720 KB |
Output is correct |
2 |
Correct |
2 ms |
5724 KB |
Output is correct |
3 |
Correct |
2 ms |
5724 KB |
Output is correct |
4 |
Correct |
2 ms |
4956 KB |
Output is correct |
5 |
Correct |
2 ms |
4956 KB |
Output is correct |
6 |
Correct |
3 ms |
5724 KB |
Output is correct |
7 |
Correct |
3 ms |
5212 KB |
Output is correct |
8 |
Correct |
3 ms |
5804 KB |
Output is correct |
9 |
Correct |
3 ms |
5724 KB |
Output is correct |
10 |
Correct |
3 ms |
5724 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
5720 KB |
Output is correct |
2 |
Correct |
2 ms |
5724 KB |
Output is correct |
3 |
Correct |
2 ms |
5724 KB |
Output is correct |
4 |
Correct |
2 ms |
4956 KB |
Output is correct |
5 |
Correct |
2 ms |
4956 KB |
Output is correct |
6 |
Correct |
3 ms |
5724 KB |
Output is correct |
7 |
Correct |
3 ms |
5212 KB |
Output is correct |
8 |
Correct |
3 ms |
5804 KB |
Output is correct |
9 |
Correct |
3 ms |
5724 KB |
Output is correct |
10 |
Correct |
3 ms |
5724 KB |
Output is correct |
11 |
Correct |
150 ms |
14728 KB |
Output is correct |
12 |
Correct |
159 ms |
14420 KB |
Output is correct |
13 |
Correct |
115 ms |
14932 KB |
Output is correct |
14 |
Correct |
119 ms |
14928 KB |
Output is correct |
15 |
Correct |
144 ms |
14592 KB |
Output is correct |
16 |
Correct |
103 ms |
14404 KB |
Output is correct |
17 |
Correct |
133 ms |
14572 KB |
Output is correct |
18 |
Correct |
163 ms |
22248 KB |
Output is correct |
19 |
Correct |
135 ms |
14820 KB |
Output is correct |
20 |
Correct |
141 ms |
14452 KB |
Output is correct |