"Factorial Calculator" Challenge

🌟 **Hello Coding Enthusiasts!**

**Challenge:** Develop a C program that calculates the factorial of a given positive integer. The factorial of a number \( n \) (denoted as \( n! \)) is the product of all positive integers from 1 to \( n \). This task will strengthen your understanding of loops and basic arithmetic operations.

**Instructions:**

1. Fork this repository.
2. Create a new branch.
3. Write a C program that takes a positive integer input from the user and calculates its factorial.
4. Ensure the program handles edge cases (like factorial of 0 or 1) and large inputs gracefully.
5. Commit your changes and submit a pull request.

**Bonus:** Implement the factorial calculation using both iterative and recursive methods and compare their efficiency.

**Happy Coding!** 🚀

*Note: This beginner-friendly issue is an excellent opportunity to practice loops and basic arithmetic operations in C!*