using System;

public class Program

{

    public static void Main()

    {

        int[] data={8, 7, 2, 1, 0, 9, 6 };

        QuickSort(data,0,data.Length-1);

        Console.WriteLine(string.Join(",",data));

    }

    private static void QuickSort(int[] data,int l,int r){

        if(l<r){

            var pivotIndex=Partition(data,l,r);

            QuickSort(data,l,pivotIndex-1);

            QuickSort(data,pivotIndex+1,r);

        }

    }

    private static void Swap(int[] data,int position1,int position2){

        var temp=data[position1];

        data[position1]=data[position2];

        data[position2]=temp;

    }

    private static int Partition(int[] data,int l,int h){

        var pivotElement=data[h];

        var pivotExchangeCounter=l-1;

        for(var i=l;i<h;i++){

            if(data[i]<pivotElement){

                pivotExchangeCounter++;

                Swap(data,i,pivotExchangeCounter);

            }

        }

        Swap(data,pivotExchangeCounter+1,h);

        return pivotExchangeCounter+1;

    }

}