Example: Array Reversal using Recursion in C

// Array Reversal using Recursion
#include <stdio.h>

// Function to print the array
void printArray(int arr[], int size) {
    for (int i = 0; i < size; i++) {
        printf("%d ", arr[i]);
    }
    printf("\n");
}

// Function to reverse the array using recursion
void reverseArrayRecursive(int arr[], int start, int end) {
    // Base condition: if start index is greater than or equal to end index,
    // the sub-array is either empty or has one element, so it's already reversed.
    if (start >= end) {
        return;
    }

    // Swap elements at start and end
    int temp = arr[start];
    arr[start] = arr[end];
    arr[end] = temp;

    // Recursive call for the rest of the array
    reverseArrayRecursive(arr, start + 1, end - 1);
}

int main() {
    // Step 1: Initialize an array
    int arr[] = {1, 2, 3, 4, 5, 6};
    int n = sizeof(arr) / sizeof(arr[0]);

    // Step 2: Print original array
    printf("Original array: ");
    printArray(arr, n);

    // Step 3: Reverse the array using the recursive function
    reverseArrayRecursive(arr, 0, n - 1);

    // Step 4: Print reversed array
    printf("Reversed array (recursive): ");
    printArray(arr, n);

    return 0;
}