package com.xiaowu.demo;

//利用递归方法求5!。

public class Demo22 {

    public static void main(String[] args) {

        int n = 5;

        long s = sum(n);

        System.out.println(n + "!= " + s);

    }

    public static long sum(int n) {

        long s = 1;

        if (n == 1||n==0) {

            s = 1;

        } else {

            s = n * sum(n - 1);

        }

        return s;

    }

}