Submission #891293

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Source Code Expand

import java.util.Scanner;

public class Main {
	void run() {
		Scanner sc = new Scanner(System.in);

		int n = sc.nextInt();
		int[] a = new int[n];
		int[] b = new int[n];
		for (int i = 0; i < n; i++) {
			int k = sc.nextInt() - 1;
			a[i] = k;
			b[k] = i;
		}
		int cnt = 0;
		for (int i = 0; i < n; i++) {
			int k = a[i];
			if (a[k] == i) {
				cnt++;
			}
		}
		System.out.println(cnt/2);
	}

	public static void main(String[] args) {
		new Main().run();
	}
}

Submission Info

Judge Result