Implementing a Simple Recursive Algorithm for Factorial Calculation

Introduction to Recursive Factorial Calculation

This tutorial will guide you through implementing a simple recursive algorithm to calculate the factorial of a given integer.

Step 1: Define the Problem and the Approach

We are given an integer and we need to calculate its factorial. We will use a recursive approach to solve this problem.

Step 2: Define the Base Case

We will define the base case for the recursion, which is when the input is 0 or 1. In this case, the factorial is 1.

if n == 0 or n == 1:
    return 1

Step 3: Define the Recursive Case

We will define the recursive case, which is when the input is greater than 1. In this case, we will call the function recursively with the input decremented by 1 and multiply the result by the current input.

else:
    return n * factorial(n - 1)

Step 4: Call the Function with the Input

Finally, we will call the function with the input and print the result.

print(factorial(5))  # Output: 120

Example Use Case

Here's an example use case:

def factorial(n):
    if n == 0 or n == 1:
        return 1
    else:
        return n * factorial(n - 1)
print(factorial(5))  # Output: 120