#include<bits/stdc++.h>

using namespace std;

int n;
int m[100001];
int x,y;
vector<int> a[100001];

int dfs(int u,int fa){
	int sum = 1;
	for(int i = 0; i < a[u].size(); i ++ ){
		if(a[u][i] != fa){
			int s = dfs(a[u][i],u);
			sum += s;
			m[u] = max(m[u],s);
		}
	} 
	m[u] = max(m[u],n-sum);
	return sum;
}

int main(){
	cin>>n;
	for(int i = 1; i < n; i ++ ){
		cin>>x>>y;
		a[x].push_back(y);
		a[y].push_back(x);
	}
	dfs(1,-1);
	int minx = 0x3f3f3f3f;
	for(int i = 1; i <= n; i ++ ){
		minx = min(minx,m[i]);
	} 
	cout<<minx;
}

求将重心删除后，剩余各个连通块中点数的最大值。

为什么WA