[数据结构与算法]for循环

package?step5;

import?java.util.Scanner;

public?class?HelloWorld?{

????public?static?void?main(String[]?args)?{

????????Scanner?sc?=?new?Scanner(System.in);

????????System.out.println("请给定一个自然数N：");

????????int?N?=?sc.nextInt();//获取输入的整数N

????????int?sum?=?1;????????

????????for(;N>=2;N-=2){

????????????sum*=N*(N-1);

????????}

????????System.out.println("自然数N的阶乘为"?+?sum);

????}

}