Quick.java

public class Quick {

  public static void main(String[] args) {
    int[] intarray = {20,35,-15,7,55,1,-22};

    quickSort(intarray, 0,intarray.length);

    for(int i = 0;i<intarray.length;i++)
    {

      System.out.println(intarray[i]);

    }


  }

  public static void quickSort(int[] input, int start, int end)
  {
    if(end-start <2)
    {
      return;
    }

    int pivotIndex = partition(input, start,end);
    quickSort(input,start,pivotIndex);
    quickSort(input,pivotIndex+1,end);


  }

public static int partition(int[] input, int start, int end)
{
  int pivot = input[start];
  int i = start;
  int j = end;
  while(i<j)
  {
    // empty loop body
    while(i<j && input[--j]>= pivot);
    if(i<j){
      input[i] = input[j];

    }
    // empty loop body
    while(i<j && input[++i] <= pivot);
    if(i<j){
        input[j] = input[i];

    }
  }
  input[j] = pivot;
  return j;

}

}