// Program to implement Shell sort
#include<iostream.h>
#include<iomanip.h>
class shellsort
{
private:
int *x;
int items;
public:
shellsort(int);
~shellsort();
void input(int [ ]);
void display();
void sort();
};
shellsort::shellsort(int n)
{
items=n;
x=new int[items];
}
shellsort::~shellsort()
{
delete [ ] x;
}
void shellsort::input(int a[ ])
{
for(int i=0;i<items;i++)
x[i]=a[i];
}
void shellsort::display()
{
cout<<"\n Sorted elements are :";
for(int i=0;i<items;i++)
cout<<setw(3)<<x[i];
}
void shellsort::sort()
{
int temp,i,h;
for(h=1;h<items/9;h=3*h+1);
for(;h>0;h /=3)
{
for(i=h;i<items;i++)
{
int j;
temp=x[i];
for(j=i-h;j>=0;j -=h)
{
if(temp<x[j])
x[j+h]=x[j];
else
break;
}
x[j+h]=temp;
}
}
}
int main()
{
int elements[100],n;
cout<<"Enter how many elements \n";
cin>>n;
cout<<"Enter"<<n<<"elements \n";
for(int i=0;i<n;i++)
cin>>elements[i];
shellsort obj(n);
obj.input(elements);
obj.sort();
obj.display();
return 0;
}
Test data
Enter how many elements
6
Enter 6 elements
90 12 68 22 11 54
Output
Sorted elements are : 11 12 22 54 68 90