java程序：编程找出m~n之间的所有完数，m和n为从键盘输入的两个整数。一个数如果恰好等于它的因子之和，这个数就称为 "完数 "。例如6=1＋2＋3。

import java.util.Scanner;

public class PerfectNumber {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("请输入m和n的值：");
        int m = input.nextInt();
        int n = input.nextInt();
        for (int i = m; i <= n; i++) {
            if (isPerfectNumber(i)) {
                System.out.println(i + "是完数");
            }
        }
    }

    public static boolean isPerfectNumber(int num) {
        int sum = 0;
        for (int i = 1; i <= num / 2; i++) {
            if (num % i == 0) {
                sum += i;
            }
        }
        return sum == num;
    }
}