Submission #894724

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Source Code Expand

#include <iostream>
#include <vector>

using namespace std;

int main() {

	long int n;
	cin >> n;
	vector<long int> friends;
	friends.resize(n);

	for(long int i = 0 ; i < n ; i++) {
			friends[i] = 0;
	}

	for(long int i = 0 ; i < n ; i++) {
		long int place;
		cin >> place;
		friends[i] = place-1;
	}

	long int counter = 0;
	for(long int j = 0 ; j < n ; j++) {
			if(friends[friends[j]] == j) {
				counter++;
			}
	}

	cout << counter/2;

	return 0;
}

Submission Info

Judge Result