Dynamic arrays

[Chewbaca10]

I have been assigned a lab where I will be shrinking and growing an array using pointers and it must be done in a function called

  void manageArray( istream& in, ostream& out )

The initial size of the array will be 10.
When the array is full, double the size of the array.
When the array is half full after a removal,reduce the size of the array by half.
I have no idea what any of this means, I haven't learned what a dynamic array is and do not know where to start. Any help is appreciated

[vlad from moscow]

I do not see any relation between the function declaration you showed and the assignment.

[Chewbaca10]

The function name isn't important, it is just specified that the work has to be done inside the function

[zeljko46]

Do you have to do it with istream and ostream? Or does it just have to be a function? If it only needs to be a function there is an almost identical program in a book called "Jumping into C++" Here's how it goes there:

int *manageArray(int *p_values,int curr_size)  /*curr_size is the size of the 
pointer,and p_values are the values of the past values*/
{
int *p_new_values = new int[ cur_size * 2 ];
for ( int i = 0; i < cur_size; ++i )
{
p_new_values[ i ] = p_values[ i ];
}
delete p_values;
return p_new_values;
}

And you use it in main like this:

int next_element = 0;
int size = 10;
int *p_values = new int[ size ];
int val;
cout << "Please enter a number: ";
cin >> val;
while ( val > 0 )
{
if ( size == next_element + 1 )
{
// now all we need to do is implement growArray
p_values = growArray( p_values, size );
}
p_values[ next_element ] = val;
cout << "Please enter a number (or 0 to exit): ";
cin >> val;
}

If you know pointers, this should be pretty clear to you ^_^ if not, read a few more tutorials.

[Chewbaca10]

Yeah it has to use ostream and istream. We use a grading program called webcat and thats the only way it works