Left Rotate Array by K Positions

#include <stdio.h>

void reverse(int *start, int *end){
    if(start == NULL || end == NULL){
        return; 
    }
    while(start < end){
        *start ^= *end;
        *end ^= *start;
        *start ^= *end;
        start++;
        end--;
    }
}

void rotate_left(int arr[], int n, int k) {
    k = k % n;
    if(arr == NULL || n <= 1 || k <= 0){
        return;
    }
    // reverse upto kth element
    reverse(&arr[0], &arr[k - 1]);
    // reverse remaining element
    reverse(&arr[k], &arr[n - 1]);
    // reverse whole array
    reverse(&arr[0], &arr[n - 1]);
}

int main() {
    int n, k;
    scanf("%d %d", &n, &k);

    int arr[100];

    // Read array elements
    for (int i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

    // Rotate the array
    rotate_left(arr, n, k);

    // Print the rotated array
    for (int i = 0; i < n; i++) {
        printf("%d", arr[i]);
        if(i < n-1){
        	printf(" ");
        }
    }

    return 0;
}