using System;
 
namespace QuickSort
{
class Program
{
public static void QuickSort(int[] array, int left, int right)
{
var i = left;
var j = right;
var pivot = array[(left + right) / 2];
while (i < j)
{
while (array[i] < pivot) i++;
while (array[j] > pivot) j--;
if (i <= j)
{
// swap
var tmp = array[i];
array[i++] = array[j];  // ++ and -- inside array braces for shorter code
array[j--] = tmp;
}
}
if (left < j) QuickSort(array, left, j);
if (i < right) QuickSort(array, i, right);
}
 
static void Main(string[] args)
{
var rand = new Random();
var array = new int[100];
for (int i = 0; i < array.Length; i++)
{
array[i] = rand.Next(1000);
}
Console.WriteLine("Before: ");
Console.WriteLine(string.Join(" ", array));
 
QuickSort(array, 0, array.Length - 1);
 
Console.WriteLine("Affter: ");
Console.WriteLine(string.Join(" ", array));
 
Console.ReadLine();
}
}
}