C++ program to find factorial using recursive function

In this article, you will learn about C++ program to find factorial using recursive function and also without using a recursive function.

We will calculate factorial of a number entered by the user with two different methods.

Let’s see how to calculate factorial of a given number.

Factorial of 5 : 1 * 2 * 3 * 4 * 5 : 120

Example: C++ program to find the factorial of a given number

//C++ program to find factorial
#include <iostream>
using namespace std;

int main()
{
   unsigned int num;
   unsigned long long fact = 1;

   cout << "Enter positive number: ";
   cin >> num;

   for (int i = 1; i <= num; i++ )
   {
      fact = fact * i;
   }

   cout << "Factorial of " << num << ": " << fact << endl;
   return 0;
}

Output

Enter positive number: 6
Factorial of 6: 720

Example: C++ program to find factorial using recursive function

//program to calculate factorial using recursion

#include<iostream>
using namespace std;

int fact(int num)
{
   if(num <= 1)
      return(1);
   else
      return(num * fact(num-1));
}

int main ()
{
   int num;

   cout << "Enter a number: ";
   cin >> num;

   cout << "\nFactorial of " << num << " is " << fact(num) << endl;

   return 0;
}

Output

Explanation

In the above program, we have created user-defined function fact that calculates the factorial of a given number using recursion.