#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
/*
C 语言实例 - 阶乘
*/


int main26()
{
    int n;
    printf("输入一个正整数: ");
    scanf("%d", &n);

    printf("%d! = %ld", n, multiplyNumbers(n));
  
    return 0;
}

long int multiplyNumbers(int n)
{

   
    if (n>1)
    {
        return n * multiplyNumbers(n - 1);
    }
    else
    {
        return 1;
    }
}