QSort.java

//Quick Sort

public class QSort {

      public static void quickSort(int[] arr, int left, int right) {
         int i = left;
         int j = right;
         int temp;
         int pivot = arr[(left+right)/2];
         while (i <= j) {
            while (arr[i] < pivot) 
               i++;
            while (arr[j] > pivot)
               j--;
            if (i <= j) {
               temp = arr[i];
               arr[i] = arr[j];
               arr[j] = temp;
               i++;
               j--;
            }
         }
         if (left < j)
            quickSort(arr, left, j);
         if (i < right)
            quickSort(arr, i, right);
      }

      public static void display(int[] arr) {
         for(int i = 0; i < arr.length; ++i) {
            System.out.println(arr[i]);
         }
      }

      public static void main(String[] args) {
         int[] data = new int[]{5,10,1,9,4,8,3,6,2,7};
         System.out.println("Unsorted array: ");
         display(data);
         quickSort(data, 0, data.length-1);
         System.out.println("Sorted array: ");
         display(data);
      }
}