Java_QuickSort

import java.util.*;

public class Main{

 private int[] data;

 private void swap(int i, int j) {

  int temp;

  temp = data[i];

  data[i] = data[j];

  data[j] = temp;

}

public void quicksort(int left, int right) {

 int i, last;

 if (left >= right)

  return;

 swap(left, (left + right) / 2);

 last = left;

 for (i = left + 1; i <= right; i++) // partitioning

  if (data[i] < data[left])

   swap(++last, i);

 swap(left, last);

 quicksort(left, last - 1);

 quicksort(last + 1, right);

}

private void printList() {

 int length = data.length;

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

   if (i == length - 1)

   System.out.println(data[i] + ".");

   else

   System.out.print(data[i] + ", ");

}

}

public static void main(String[] args) {

  Main sort = new Main();

  sort.data = new int[]{24, 2, 45, 20, 56, 75, 16, 56, 99, 53, 12};

   int length = sort.data.length;

   System.out.println("unsorted list.");

   sort.printList();

   sort.quicksort(0, length - 1);

  System.out.println("sorted list.");

  sort.printList();

}

}