Merge Sort - input from user

#include <stdio.h>

void merge(int arr[], int left[], int leftSize, int right[], int rightSize) {
    int i = 0, j = 0, k = 0;

    while (i < leftSize && j < rightSize) {
        if (left[i] < right[j]) {
            arr[k++] = left[i++];
        } else {
            arr[k++] = right[j++];
        }
    }

    while (i < leftSize) {
        arr[k++] = left[i++];
    }

    while (j < rightSize) {
        arr[k++] = right[j++];
    }
}

void mergeSort(int arr[], int size) {
    if (size > 1) {
        int mid = size / 2;
        int left[mid];
        int right[size - mid];

        for (int i = 0; i < mid; i++) {
            left[i] = arr[i];
        }
        for (int i = mid; i < size; i++) {
            right[i - mid] = arr[i];
        }

        mergeSort(left, mid);
        mergeSort(right, size - mid);
        merge(arr, left, mid, right, size - mid);
    }
}

int main() {
    int size;

    printf("Enter the number of elements: ");
    scanf("%d", &size);

    int arr[size];

    printf("Enter %d integers separated by spaces: ", size);
    for (int i = 0; i < size; i++) {
        scanf("%d", &arr[i]);
    }

    printf("Original Array: ");
    for (int i = 0; i < size; i++) {
        printf("%d ", arr[i]);
    }

    mergeSort(arr, size);

    printf("\nSorted Array: ");
    for (int i = 0; i < size; i++) {
        printf("%d ", arr[i]);
    }

    return 0;
}