12a Bubble sort

#include <iostream>
using namespace std;

template <class X> 
void bubble(X *items,int count)
{
 
  register int a, b;
  X t;
  for(a=1; a<count; a++)
    for(b=count-1; b>=a; b--)
      if(items[b-1] > items[b]) 
      {
       // exchange elements
        t = items[b-1];
        items[b-1] = items[b];
        items[b] = t;
      }

}
int main() 
{
    int iarray[7] = {7, 5, 4, 3, 9, 8, 6};
    double darray[5] = {4.3, 2.5, -0.9, 100.2, 3.0};
    int i;
    cout << "Here is unsorted integer array: ";
    for(i=0;  i<7; i++)
        cout << iarray[i] << ' ';
    cout << endl;
    cout << "Here is unsorted double array: ";
    for(i=0;  i<5; i++)
        cout << darray[i] << ' ';
    cout << endl;

    bubble(iarray, 7);
    bubble(darray, 5);
    
    cout << "Here is sorted integer array: ";

    for(i=0;  i<7; i++)
        cout << iarray[i] << ' ';

    cout << endl;
    cout << "Here is sorted double array: ";

    for(i=0;  i<5; i++)
        cout << darray[i] << ' ';

    cout << endl;
    return 0; 
}