C Program to Find Factorial of a Given Number Using User Defined Function

#include<stdio.h>
#include<conio.h>

/* Function Prototype */
long int fact(int n);

/* Main function */
int main()
{
	 long int number, result;

	 /* Input */
	 printf("Enter any positive integer: ");
	 scanf("%ld", &number);

	 /* Function call */
	 result = fact(number);
	 printf("%ld != %ld",number,result);
	 return(0);
}

long int fact(int n)
{
    long int i, f=1;
    for(i=1;i<= n;i++)
	 {
	  f = f*i;
	 }
	 return f;
}

Output 

Enter any positive integer: 12
12 != 479001600