Factorial program in c without recursion

• Factorial of n= n*n-1*.....1
• To find factorial of a number in c programming language we need to use for loop and iterate from n to 1 
• in side loop we need to write a logic to multiply the result.
•  factorial *= i;    
• Finally in  factorial  we will have the result of  1 *2 *.....n
• Let us see an example c program on finding factorial of a number without using recursion. 

 Program #1: Write a c program to print factorial of a number without using recursion.

1. #include <stdio.h>
2. #include <stdlib.h>
3.  
4. int main()
5. {
6.     int n, i;
7.     unsigned long long factorial = 1;
8.  
9.     printf("Enter a number to find factorial: ");
10.     scanf("%d",&n);
11.  
12.     // show error if the user enters a negative integer
13.     if (n < 0)
14.         printf("Error! Please enter any positive integer number");
15.  
16.     else
17.     {
18.         for(i=1; i<=n; ++i)
19.         {
20.             factorial *= i;              // factorial = factorial*i;
21.         }
22.         printf("Factorial of Number %d = %llu", n, factorial);
23.     }
24.  
25.     getch();
26. }

Output: