20140506_KUAS_VisualC++_Factorial

/************************************/
/** 20140506 Factorial             **/
/** Maker  : Yan                   **/
/** E-Mail : [email protected] **/
/** Date   : 2014/05/26 am.11:12   **/
/************************************/

#include <stdio.h>
#include <stdlib.h>

int factorial(int, int);

void main()
{
    printf("Enter a number of factorial: ");
    int input = 0, sum = 1;
    scanf("%d", &input);
    printf("Factorial results = %d.\n", factorial(input, sum));
    system("pause");
}

int factorial(int input, int sum)
{
    if(input >= 1)
    {
        sum = sum * input--;
        factorial(input, sum);
    }
    else
    {
        return sum;
    }
}