Example: Recursive Fibonacci in C++

C
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Java
Python
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// Recursive Fibonacci
#include <iostream>

// Function to calculate the nth Fibonacci number recursively
int fibonacci(int n) {
    // Base cases:
    // The first Fibonacci number (at index 0) is 0.
    if (n == 0) {
        return 0;
    } 
    // The second Fibonacci number (at index 1) is 1.
    else if (n == 1) {
        return 1;
    } 
    // Recursive step: Sum of the two preceding numbers.
    else {
        return fibonacci(n - 1) + fibonacci(n - 2);
    }
}

int main() {
    // Step 1: Print the first 10 Fibonacci numbers
    std::cout << "Fibonacci Sequence (first 10 numbers):" << std::endl;
    for (int i = 0; i < 10; ++i) {
        std::cout << fibonacci(i) << " ";
    }
    std::cout << std::endl;

    // Step 2: Test with a specific number
    int num = 7;
    std::cout << "The " << num << "th Fibonacci number is: " << fibonacci(num) << std::endl;

    return 0;
}