Submission #891422

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Source Code Expand

#include <bits/stdc++.h>
#define ln(S) (S).length()
using namespace std;

typedef long long llint;

int n;
int a[100100];

int main(){
	cin >> n;

	for (int i = 1; i <= n; ++i)
	{
		cin >> a[i];
	}

	int ans = 0;
	for (int i = 1; i <= n; ++i)
	{
		if (a[a[i]] == i)
			ans++;
	}

	cout << ans/2;

	return 0;
}

Submission Info

Judge Result