Program to illustrate the Quick Sort

 # include <iostream.h>
 # include <conio.h>

 void swap(long &,long &);
 void quick_sort(long [],int,int);


 main( )
    {
       clrscr( );

       const int array_size=10;

       long array[array_size]={0};

       cout<<\"\\n ******************************************************************************\"<<endl;
       cout<<\" ********************************  Quick Sort  ******************************\"<<endl;
       cout<<\" ******************************************************************************\"<<endl;

       cout<<\"\\n * Array size = 10\"<<endl;
       cout<<\" * Data Type = long\"<<endl;

       gotoxy(1,24);
       cout<<\" ******************************************************************************\";
       gotoxy(1,25);
       cout<<\" ******************************************************************************\";

       gotoxy(1,10);
       cout<<\" Enter the array : \"<<endl<<endl;

       for(int count_1=0;count_1<array_size;count_1++)
      {
         cout<<\"\\t Element[\"<<count_1<<\"] = \";
         cin>>array[count_1];
      }

       quick_sort(array,0,array_size-1);

       gotoxy(40,10);
       cout<<\" Sorted Array : \";

       for(int count_2=0;count_2<array_size;count_2++)
      {
         gotoxy(50,12+count_2);
         cout<<\"Element[\"<<count_2<<\"] = \"<<array[count_2]<<endl;
      }

       getch( );
       return 0;

    }



 /***********************  Function Definitions  **************************/




 //--------------------------  swap(long,long)  --------------------------//


 void swap(long &element_1,long &element_2)
    {
       long temp=element_1;
       element_1=element_2;
       element_2=temp;
    }


 //--------------------  quick_sort(long [],int,int)  --------------------//


 void quick_sort(long array[],int first,int last)
    {
       if(first>=last)
      {  }

       else
      {
         int middle=array[last];
         int count_1=first-1;
         int count_2=last;

         while(count_1<count_2)
        {
           do
              {
             count_1++;
              }
           while(array[count_1]<middle);

           do
              {
             count_2--;
              }
           while(count_2>=0 && array[count_2]>middle);

           if(count_1<count_2)
             swap(array[count_1],array[count_2]);
        }

         swap(array[count_1],array[last]);

         quick_sort(array,first,count_1-1);
         quick_sort(array,count_1+1,last);
      }
    }