Submission #891383

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Source Code Expand

#include <iostream>
using namespace std;
const int maxn = 100000;
int n,a[maxn+1];
int main() 
{
	ios_base::sync_with_stdio(0);
	cin >> n;
	for (int i=1; i<=n; i++)
	cin >> a[i];
	int dem=0;
	for (int i=1; i<=n; i++)
	if (a[a[i]]==i) dem++;
	cout << dem/2;
	return 0;
}

Submission Info

Judge Result