题解 | #完全数计算#

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNextInt()) {
            int n = sc.nextInt();
            int count = 0;
            for (int i = 1; i <= n; i++) {
                if (getPerfectNum(i)) {
                    count++;
                }
            }
            System.out.println(count);
        }
    }

    private static boolean getPerfectNum(int i) {
        ArrayList<Integer> list = new ArrayList<>();
        for (int j = 1; j < i; j++) {
            if (i % j == 0) {
                list.add(j);
            }
        }
        int sum = 0;
        for (Integer integer : list) {
            sum += integer;
        }
        return sum == i;
    }

}