阶乘

import java.util.Scanner;

public class 阶乘 { public static void main(String[] args) {

    Scanner sc = new Scanner(System.in);

    System.out.println("输入一个数字");

int n = sc.nextInt();

    System.out.println("结果为："+f(n));

} public static int f(int n){

    int sum = 1;

    for(int i = 1;i <= n;++i){

        sum *= i; 

    }

    return sum;

}