Submission #891660

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Source Code Expand

#include<bits/stdc++.h>
using namespace std;

int main() {
	int N;
	cin >> N;
	vector<int> v(N);
	for (int i = 0; i < N; i++) {
		cin >> v[i];
		v[i]--;
	}
	int s = 0;
	for (int i = 0; i < N; i++) {
		if (v[v[i]] == i) {
			s++;
		}
	}
	cout << s/2 << endl;
	return 0;
}

Submission Info

Judge Result