递归算法Recursion algorithm

import java.util.Scanner;
//factorial 阶乘

/**
* @author Administrator
* 计算一个数的阶乘
*/
public class Factorial {

public static void main(String[] args) {
System.out.println("input a integer:");
Scanner input = new Scanner(System.in);
int number = input.nextInt();
System.out.println("factorial is: " + factorial(number));
}

/**
* @author Administrator
* @param number为要计算阶乘的数
* @return 返回该数的阶乘
*/
public static double factorial(int number){
if(number == 0){
return 1;
}else{
return number * factorial(number - 1);
}
}
}