Tietoverkko

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
#define N (1<<20)

int t[N], z[N];
vector<int> v[N];
int V = 0;

void haku(int s, int h){
	z[s] = h;
	for(int i : v[s]){
		if(!z[i]) haku(i, h+1);
		else if(z[i] < h-1) V = h - z[i] + 1;
	}
}

int main(){
	int n; 
	cin >> n;
	int m =n;
	while(m--){
		int a, b; cin >> a >> b;
		v[a].push_back(b);
		v[b].push_back(a);
	}
	haku(1, 1);
	cout << n - V;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED