Merge Sort (Iteration)

/*********************************************************

-> This C++ program is to perform Merge sort
   using iterative method.

-> This program works in microsoft vc++ 6.0 environment.

-> The numbers are sorted in increasing order.

**********************************************************/

#include<iostream.h>
class sorting
{
private:
 double *array;
 int n;
 public:
 void input();
 void output();
 void mergesort();
};

void sorting::input()
{
 cout<<”****************************************************\n”
  <<”This program sorts numbers in increasing order”
  <<”\n\t\tusing Merge sort iterative technique\n”
  <<”****************************************************\n”;

 cout<<”Enter how many numbers you are going to enter for sorting ::”;
 cin>>n;
 array=new double[n];
 cout<<”Now enter your elements ::\n”;
 for(int i=0;i<n;i++)
  cin>>array[i];
}

void sorting::mergesort()
{
 double *temp=new double[n];
 int l1,l2,u1,u2,i;
 int size=1,j,k;
 while(size<n)
 {
          l1=0;
           k=0;
           while(l1+size<n)
           {
                    l2=l1+size;
                    u1=l2-1;
                    u2=(l2+size-1<n)?l2+size-1:n-1;
                    for(i=l1,j=l2;i<=u1&&j<=u2;k++)
                            if(array[i]<=array[j])
                            temp[k]=array[i++];
                            else
                            temp[k]=array[j++];
                    for(;i<=u1;k++)
                        temp[k]=array[i++];
                    for(;j<=u2;k++)
                        temp[k]=array[j++];
                    l1=u2+1;
           }
            for(i=l1;k<n;i++)
                temp[k++]=array[i];
            for(i=0;i<n;i++)
                array[i]=temp[i];

            size*=2;
 }
}

void sorting::output()
{
 cout<<”Now the sorted numbers are ::\n”;
 for(int i=0;i<n;i++)
  cout<<array[i]<<’\t’;
 cout<<endl;
}

int main()
{
 sorting obj;
 obj.input();
 obj.mergesort();
 obj.output();
 return 0;
}
/**********************************************************************

****************************************************
This program sorts numbers in increasing order
                using Merge sort iterative technique
****************************************************
Enter how many numbers you are going to enter for sorting ::7
Now enter your elements ::
1.7
1.6
1.5
1.4
1.3
1.2
1.1
Now the sorted numbers are ::
1.1     1.2     1.3     1.4     1.5     1.6     1.7
Press any key to continue

************************************************************************/