Factorial of a number in C language

 WAP to find the factorial of a given number.

Assume we want to calculate the factorial of 5. We can write it as 5! and it can be calculated as follows:
5! = 5 x 4 x 3 x 2 x 1
= 120
Therefore, the factorial of 5 is 120.

#include <stdio.h>

#inlude<conio.h>

void main() 

{

    int n, i;

    long fact = 1;

    clrscr();

    printf("Enter an integer: ");

    scanf("%d", &n);

   // shows error if the user enters a negative integer

    if (n < 0)

        printf("Error! Factorial of a negative number doesn't exist.");

    else 

    {

        for (i = 1; i <= n; ++i) 

        {

            fact=fact * i;

        }

        printf("Factorial of %d = %ld", n, fact);

    }

    getch();

}

Output

Enter an integer: 5

Factorial of 5 = 120