C Program - to find the factorial of a number by both the recursive method and Iterative Method

C Programming Language Recursion in c (Article) Recursion in c (Program)

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Program:

#include<stdio.h>
long int fact(int n);
long int Ifact(int n);
main( )
{
int num;
printf("Enter a number : ");
scanf("%d", &num);
if(num<0)
	printf("No factorial for negative number\n");
else
	printf("Factorial of %d is %ld\n", num, fact(num) );
	
if(num<0)
	printf("No factorial for negative number\n");
else
	printf("Factorial of %d is %ld\n", num, Ifact(num) );
}/*End of main()*/


/*Recursive*/
long int fact(int n)
{
	if(n == 0)
		return(1);
	return(n * fact(n-1));
}/*End of fact()*/


/*Iterative*/
long int Ifact(int n)
{
	long fact=1;
	while(n>0)
	{
		fact = fact*n;
		n--;
	}
return fact;
}/*End of ifact()*/

Output:

Enter a number : 5
Factorial of 5 is 120
Factorial of 5 is 120
Press any key to continue . . .

Explanation:

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