An efficient algorithm to left-rotate an array by k

leftRotateArray.cpp

#include <iostream>
using namespace std;

void reverseArray(int *array, int start, int end) {
    for (int i = start, j = end - 1; i < j; i++, j--) {
        array[i] = array[i] ^ array[j];
        array[j] = array[i] ^ array[j];
        array[i] = array[i] ^ array[j];
    }
}

// most efficient algorithm
void leftRotate(int *array, int n, int k) {

    // reverse the first part of the array (upto k)
    reverseArray(array, 0, k);
    // reverse the second part
    reverseArray(array, k, n);

    // then the entire one
    reverseArray(array, 0, n);

}

int main() {

    int myArray[] = {1, 2, 3, 4, 5, 6, 7};
    int n = sizeof(myArray) / sizeof(myArray[0]);
    int k = 3;

    //reverseArray(myArray, 0, n);
    leftRotate(myArray, n, k);

    for (int i = 0; i < n; i++) {
        cout << myArray[i] << " ";
    }

    return 0;

}