This is a simple C++ program that performs two mathematical operations based on user input:

1. Factorial Calculation – Computes the factorial of a positive integer.
2. Fibonacci Series Generation – Displays the Fibonacci series up to the entered number of terms.

It uses iterative logic for both operations and ensures basic input validation.

• Calculates the factorial using a loop.
• Prints the Fibonacci series without using arrays or vectors.
• Validates the input to ensure it's a non-negative integer.
• Clean and modular code with separate functions for each task.

g++ main.cpp -o math_calculator
./math_calculator