To print double of each element in an Array

#include<conio.h>
#include<iostream.h>
# define r 3
void main()
{ clrscr();
  int a[r];
  for (int i=0;i<r;i++)
      { cin>>a[i];
      }
  for (i=0;i<r;i++)
      { cout<<2*a[i]<<" - ";
      }
  getch();
}