Quick Sort

$$$ QUICK SORT $$$

PROGRAM:

#include<iostream>

int i,a[20],n;

class quicksort

{

public:

void getdata()

{

      cout<<"\nEnter the array limit:";

      cin>>n;

      cout<<"Enter array elements:";

      for(i=0;i<n;i++)

      {

            cin>>a[i];

      }

}

void qsort(int a[],int left,int right)

{

      int i,j,pivot,temp;

      if(left<right)

      {

            pivot=left;

            i=left+1;

            j=right;

            for(;;)

            {

                  while(a[i]<=a[pivot])

                        i=i+1;

                  while(a[j]>a[pivot])

                        j=j-1;

                  if(i<j)

                  {

                        temp=a[i];

                        a[i]=a[j];

                        a[j]=temp;

                  }

                  else

                  {

                        break;

                  }

            }

            temp=a[pivot];

            a[pivot]=a[j];

            a[j]=temp;

            qsort(a,left,j-1);

            qsort(a,j+1,right);

      }

}

void putdata()

{

      cout<<"The Sorted elements are:\t";

      for(i=0;i<n;i++)

      {

            cout<<a[i]<<"\t";

      }

}

};

void main()

{

      quicksort qs;

      cout<<"$$$ QUICK SORT $$$";

      qs.getdata();

      qs.qsort(a,0,n-1);

      qs.putdata();

}

OUTPUT:

$$$ QUICK SORT $$$
Enter the array limit:       8
Enter array elements:    40           20           70           14           60           61           97           30
The Sorted elements are:            14           20           30           40           60           61           70           97