QuickSort

public class QuickSort {
      Random  rand =  new Random();
    public int[] quickSort(int[] array) {
        if (array == null || array.length = 0) {
            return array;
        }
        quickSort(int[] array,0, array.length -1)
            return array;
    }
    private void quickSort(int[] array, int left, int right) {
        if (left >= right){
            return;
        }
        int pivot = partition(array, left, right);
        quickSort(array, left, pivot - 1);
        quickSort(array, pivot + 1, right);
    }
    private void partition(int[] array, int left, int right){
        int pivotIndex = left + rand.nextInt(right - left)/2;
        int pivot = array[pivotIndex];
        swap(array, pivot, pivotIndex);
        int leftIndex = left;
        int rightIndex = right -1;
        while (leftIndex >= rightIndex){
                       if (array[leftIndex] < pivot){
                leftIndex++;
                       } else if (array[rightIndex] > pivot){
                             rightIndex--;
                       } else {
                          swap(array, leftIndex, rightIndex);
            }
        }
                  sawap(array, leftIndex, pivot);
               return leftIndex;
        }

    private void swap(int[] array, int left, int right){
            int temp = array[left];
            array[left] = array[right];
            array[right] = temp;
    }
}