java - java中的完美数使用方法做作业

Question

我要为类写作业，但被困住了，不知道如何正确设置它，就像它应该的那样。我很感谢我得到的任何帮助，谢谢。这是作业:

An integer number is said to be a perfect number if its factors, including 1 (but not the numbers itself), sum to the number. For example,6 is a perfect number, because 6=1+2+3. Write method Perfect that determines whether number is a perfect number. Use this method in an application that determines and displays all the perfect numbers between 2 and 1000. Display the factors of each perfect number to confirm that the number is indeed perfect.

输出:

6 is perfect.
Factors:1 2 3
28 is perfect.
Factors: 1 2 4 7 14
496 is perfect.
Factors: 1 2 4 8 16 31 62 124 248

这是我遇到的代码:

public class Homework4 {

    public static void main(String[] args) {

        for(int num=2;num<=1000;num++)
        {
            if(perfect(num))
            {
                System.out.println(num + " is perfect.");
                System.out.printf("Factors: ",perfect(num));

            }

        }
    }
        public static Boolean perfect(int num)
        {
            int sum = 0;

            for(int i=1;i<num;i++)
            {
                if (num % i == 0)
                {
                    sum+=i;
                }
            }
            if(num==sum)
            {
            for(int i=1;i<num;i++)
            {
                if (num % i == 0)
                {
                    System.out.print(i+" ");
                }
            }


            }
            return sum==num;
        }

}

运行:

1 2 3 6 is perfect.
1 2 3 Factors: 1 2 4 7 14 28 is perfect.
1 2 4 7 14 Factors: 1 2 4 8 16 31 62 124 248 496 is perfect.
1 2 4 8 16 31 62 124 248 Factors: BUILD SUCCESSFUL (total time: 0 seconds)

Answer 1

有两种方法可以解决此问题。

• 您可以将 perfect 方法分解为两个单独的方法 - 一种方法检查数字是否完美，另一种方法打印其因子。检查时调用第一个 - 如果返回 true，则调用第二个。

或者

• 您可以将打印 ... is Perfect 的行移动到方法本身中。然后从 main 中删除整个 if block 。