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);
}
}