Example: Fibonacci Series - Recursive Method in C

// Fibonacci Series - Recursive Method
#include <stdio.h>

// Function to calculate the nth Fibonacci number recursively
int fibonacci(int n) {
    // Step 1: Define base cases for the recursion.
    if (n == 0) {
        return 0;
    } else if (n == 1) {
        return 1;
    } else {
        // Step 2: Recursive step - sum of the two preceding Fibonacci numbers.
        return (fibonacci(n - 1) + fibonacci(n - 2));
    }
}

int main() {
    // Step 1: Declare variables for the number of terms and loop counter.
    int n, i;

    // Step 2: Prompt the user to enter the number of terms.
    printf("Enter the number of terms: ");
    scanf("%d", &n);

    // Step 3: Print a message indicating the series.
    printf("Fibonacci Series: ");

    // Step 4: Loop to call the recursive function for each term.
    for (i = 0; i < n; i++) {
        // Step 4.1: Call the fibonacci function and print the result.
        printf("%d, ", fibonacci(i));
    }
    printf("\n"); // Newline for better formatting
    return 0;
}