java - java打印阶乘计算过程

Question

嗨，我需要打印阶乘计算过程。例如。如果用户输入的是5，系统应该打印出“5 * 4 * 3 * 2 * 1 = 120”

我有这个代码:

 public static void factorial()
{
    Scanner sc = new Scanner(System.in);
    int factorial = 1;
    int count;

    System.out.println(me+", This is option 2: Calculate a factorial");
    System.out.print("Enter your number: ");
    int number = sc.nextInt();
    System.out.println();

    if (number>0)
        {
            for (count=1; count<=number; count++)

            factorial = factorial*count;

            System.out.println(" = "+factorial);
            System.out.println();
        }
    else
    {
        System.out.println("Enter a positive whole number greater than 0");
        System.out.println();
    } 

}    

我尝试插入此代码:

 System.out.print(count+" * ");

但是输出是“1 * 2 * 3 * 4 * 5 * = 6”。所以结果也是错误的。我怎样才能更改代码？谢谢

Answer 1

问题是您没有在 for 语句中添加大括号 {}:

if (number>0)
{
    for (count=1; count<=number; count++)
    {
        factorial = factorial*count;
        System.out.print(count);
        if(count < number)
            System.out.print(" * ");
    }

    System.out.println("Factorial of your number is "+factorial);
    System.out.println();
}

此外，如果您担心顺序(1,2,4,5 而不是 5,4,3,2,1)，您可以执行以下操作(更改 for 循环):

if (number>0)
{
    for (count=number; count>1; count--)
    {
        factorial = factorial*count;
        System.out.print(count);
        if(count > 2)
            System.out.print(" * ");
    }

    System.out.println("Factorial of your number is "+factorial);
    System.out.println();
}