算法练习之阶乘

要求：对于一个非负数，求它的阶乘

使用递归

JavaScript版：

function factorialize(num) {
    if(num === 0){
        num = 1;
    }else if(num == 1 || num == 2){
        num *= 1;
    }else{
        return num*factorialize(num-1);
    }
return num;
}

console.log(factorialize(5));//120

java版：

public class Test{
    public static void main(String[] args) {
        System.out.println(factorialize(5));;
    }

    private static int factorialize(int n) {
        if(n == 0){
            n = 1;
        }else if(n == 1 || n == 2){
            n *= 1;
        }else{
            return n*factorialize(n-1);
        }
        return n;
    }

}