public class QuickSortExample 
{
    public static void main(String[] args) 
    {
        // This is unsorted array
        Integer[] array = new Integer[] { 12, 13, 24, 10, 3, 6, 90, 70 };
 
        // Let's sort using quick sort
        quickSort( array, 0, array.length - 1 );
 
        // Verify sorted array
        System.out.println(Arrays.toString(array));
    }
 
    public static void quickSort(Integer[] arr, int low, int high) 
    {
        //check for empty or null array
        if (arr == null || arr.length == 0){
            return;
        }
         
        if (low >= high){
            return;
        }
 
        //Get the pivot element from the middle of the list
        int middle = low + (high - low) / 2;
        int pivot = arr[middle];
 
        // make left < pivot and right > pivot
        int i = low, j = high;
        while (i  pivot) 
            {
                j--;
            }
            //Now compare values from both side of lists to see if they need swapping 
            //After swapping move the iterator on both lists
            if (i  i){
            quickSort(arr, i, high);
        }
    }
     
    public static void swap (Integer array[], int x, int y)
    {
        int temp = array[x];
        array[x] = array[y];
        array[y] = temp;
    }
}
 
//Output: [3, 6, 10, 12, 13, 24, 70, 90]