Submission #1231167

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Source Code Expand

/* 09:26 - 09:29 */

#include <iostream>
#include <vector>

using namespace std;

int main(void) {

	int n; cin >> n;
	vector<int> like(n);

	for (int i = 0; i < n; ++i) {
		cin >> like[i];
		--like[i];
	}

	int count = 0;
	for (int i = 0; i < n; ++i) {
		count += (like[like[i]] == i);
	}

	cout << count / 2 << endl;
	return 0;

}

Submission Info

Judge Result