C Program to calculate factorial using recursion

Interview Preparation

In this tutorial, we will learn to write the program to find the factorial of numbers using the C programming language. Here we are going to follow a recursive approach.

What is Factorial of a number?

Factorial of a whole number ‘n’ is the product of that number ‘n’ with its every whole number in descending order till 1.

For example

Factorial of 5 is 5*4*3*2*1 = 120

And factorial of 5 can be written as 5!.

Factorial Program in C of a given number using Recursion

#include<stdio.h>
long long fact(int num){
  if (num == 0)
    return 1;
  else
    return(num * fact(num-1));
}
int main()
{
 int i,num,factorial=1;
 printf("Enter a whole number to find Factorial = ");
 scanf("%d",&num);
  printf("Factorial of %d is: %llu",num,fact(num));
return 0;
}

Output

C Program to calculate factorial using recursion