QuickSort.java

class QuickSort
{
  int partition(int arr[], int lowIndex, int highIndex)
  {
    int pivot = arr[highIndex];
    int i = (lowIndex-1);
    for (int j=lowIndex; j<highIndex; j++)
    {
      if (arr[j] <= pivot)
    {
    i++;
    int temp = arr[i];
    arr[i] = arr[j];
    arr[j] = temp;
  }
}
  int temp = arr[i+1];
  arr[i+1] = arr[highIndex];
  arr[highIndex] = temp;
  return i+1;
}

void sort(int arr[], int lowIndex, int highIndex)
{
  if (lowIndex < highIndex)
  {
    int pi = partition(arr, lowIndex, highIndex);
    sort(arr, lowIndex, pi-1);
    sort(arr, pi+1, highIndex);
  }
}

static void printArray(int arr[])
{
  int n = arr.length;
  for (int i=0; i<n; ++i)
  System.out.print(arr[i]+" ");
  System.out.println();
}

public static void main(String args[])
 {
  int arr[] = {101, 37, 68, 29, 11, 5};
  int n = arr.length;
  QuickSort ob = new QuickSort();
  ob.sort(arr, 0, n-1);
  System.out.println("sorted array");
  printArray(arr);
  }
}