How does recursion work in C++ for calculating Fibonacci numbers?

Can you explain how recursion works in C++ for calculating Fibonacci numbers?

Sure! Recursion in C++ allows a function to call itself. For Fibonacci, we define a function that returns the sum of the two preceding numbers.

Could you show me a simple code example?

Absolutely! Here's a basic example:

int fibonacci(int n) {
    if (n <= 1) return n;
    return fibonacci(n - 1) + fibonacci(n - 2);
}

What are the drawbacks of using recursion for this?

The main drawback is that it can be inefficient for large n due to repeated calculations. Using memoization or an iterative approach can help.

How can I optimize this recursive function?

You can optimize it using memoization, which stores previously computed values to avoid redundant calculations.