Program To Calculate Factorial of a Number using Function

In mathematics,the factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n. For example, 5 ! = 5 × 4 × 3 × 2 × 1 = 120.

	#include <stdio.h>
	int factorial(int num);
	int main()
	{
		int num,fn;
		printf("Enter the number :");
		scanf("%d",&num);
		fn=factorial(num);
		printf("Factorial Number of %d is %d",num,fn);
		printf("\nEnter another number :");
		scanf("%d",&num);
		fn=factorial(num);
		printf("Factorial Number of %d is %d",num,fn);
		return 0;
	}
	int factorial(int num)
	{
		int fn=1;
		while(num>=1)
		{
			fn=fn*num;
			num--;
		}
		return fn;
	}

Output

	Enter the number :9
	Factorial Number of 9 is 362880
	Enter another number :12
	Factorial Number of 12 is 479001600
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