Example: Array Sum using Recursion in C

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

// Recursive function to sum array elements
// arr: pointer to the current start of the sub-array
// n: number of elements remaining in the sub-array
int sumArrayRecursive(int *arr, int n) {
    // Step 1: Base Case - If no elements are left, the sum is 0
    if (n <= 0) {
        return 0;
    }
    // Step 2: Recursive Step - Add the first element to the sum of the rest of the array
    return arr[0] + sumArrayRecursive(arr + 1, n - 1);
}

int main() {
    int arr[] = {10, 20, 30, 40, 50};
    int n = sizeof(arr) / sizeof(arr[0]);

    int sum = sumArrayRecursive(arr, n);

    printf("The sum of array elements using recursion is: %d\n", sum);

    return 0;
}