递归n!

package sushudigui;

import java.util.Scanner;

public class digui {
    public static void main(String[] args){
        System.out.println("输入n，按回车：");
        Scanner s = new Scanner(System.in);
        Integer n = Integer.parseInt(s.next());
        Integer re = factorial(1, n);
        System.out.println(re);
    }
    public static Integer factorial(Integer a, Integer b){
        if(b == 1){
            return a * b;
        }else{
            return a * b * factorial(a, b-1);
        }
    }

}