Submission #23637453

Source Code Expand

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import java.util.*;
public class Main {
  public static void main(String[] args) {
    // 入力
    Scanner sc = new Scanner(System.in);
    int n = Integer.parseInt(sc.next());
    int[] a = new int[n + 1];
    for (int i = 1; i <= n; i++) {
      a[i] = Integer.parseInt(sc.next());
    }
    // 各うさぎについて
    int result = 0;
    for (int i = 1; i <= n; i++) {
      if (i < a[i] && a[a[i]] == i) {
        result++;
      }
    }
 
 
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import java.util.*;

public class Main {

	public static void main(String[] args) {

		// 入力
		Scanner sc = new Scanner(System.in);
		int n = Integer.parseInt(sc.next());
		int[] a = new int[n + 1];
		for (int i = 1; i <= n; i++) {
			a[i] = Integer.parseInt(sc.next());
		}

		// 各うさぎについて
		int result = 0;
		for (int i = 1; i <= n; i++) {
			if (i < a[i] && a[a[i]] == i) {
				result++;
			}
		}
		System.out.println(result);

	}
}

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