题目：利用递归方法求5!。

import java.util.Scanner;
//欢迎大家多提宝贵意见;我会仔细学习的;
/*
题目：利用递归方法求5!。   
1.程序分析：递归公式：fn=fn_1*4!*/
public class Recursion1 {
	public static int DoFactorial(int n){
		System.out.print(n+"! = ");
		int sum =1;
		if(n <= 0){
			System.out.println("输入错误,必须大于0;/n请重新输入");
		}else{
			for(int i = n;i > 0;i--){
				if(i == 1){
					sum *=i;
					System.out.print(i+"=");
				}else{
					sum *=i;
					System.out.print(i+"*");
				}
			}
		}
		return sum;
	}
	public static void main(String[]args){
		System.out.println("请输入您要求阶乘的数字n=");
		Scanner in = new Scanner(System.in);
		int m = in.nextInt();
		System.out.println(DoFactorial(m));
		//Recursion1 r1 = new Recursion1();
		//r1.DoFactorial(m);
	}
}