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OI-codes/AcWing/846/846.cpp

47 lines
741 B
C++

#include <iostream>
#include <limits>
#include <vector>
using std::cin;
using std::cout;
const char endl = '\n';
const int N = 100005;
int n, ans = std::numeric_limits<int>::max();
std::vector<int> g[N];
int dfs(int u, int fa) {
int siz = 0, sum = 0;
for (int v : g[u]) {
if (v != fa) {
int s = dfs(v, u);
siz = std::max(siz, s);
sum += s;
}
}
ans = std::min(ans, std::max(siz, n - sum - 1));
return sum + 1;
}
int main() {
std::ios::sync_with_stdio(false);
cin >> n;
for (int i = 1, u, v; i < n; i++) {
cin >> u >> v;
g[u].push_back(v);
g[v].push_back(u);
}
dfs(1, -1);
cout << ans << endl;
return 0;
}