using System;

public class Program

{

    public static void Main()

    {

        int[] arr=new int[]{10, 80, 30, 90, 40, 50, 70};

        Sorting s=new Sorting();

        s.QuickSort(arr,0,arr.Length-1);

        for(int i=0;i<arr.Length;i++){

            Console.WriteLine(arr[i].ToString());

        }

    }

    public class Sorting

    {

        public void QuickSort(int[] arr,int low,int high){

            if(low<high){

                int p=Partition(arr,low,high);

                QuickSort(arr,low,p-1);

                QuickSort(arr,p+1,high);

            }   

        }

        public int Partition(int[] arr,int low,int high){

            int i=low-1;

            int pivot=arr[high];

            for(int j=low;j<=high-1;j++){

                if(arr[j]<=pivot){

                    i++;

                    Swap(arr,i,j);

                }

            }

            Swap(arr,(i+1),high);

            return (i+1);

        }

        public void Swap(int[] arr,int i,int j){

            int temp=arr[i];

            arr[i]=arr[j];

            arr[j]=temp;

        }

    }

}