If there is truly a legitimate reason for a subclass to want to access a field, it should be declared "protected".

These are identical. It is a pointer in both cases. So I guess it may be more clear to write it as a pointer. The second case might cause beginners to think that you are passing an entire array by...

Also, a fundamental problem with your grow() function:

The last line is completely useless, because "array" is a local variable, assigning it has no effect outside the function.

wow.

what did you expect that code to do?

except that it doesn't check bounds

just download it from the sourceforge project
http://sourceforge.net/projects/dev-cpp/

you need to make the method in the base class virtual
http://en.wikipedia.org/wiki/Virtual_function

note that with any two numbers a and b, a * b = gcd(a, b) * lcm(a, b)

maybe you are using a C compiler instead of C++

I think this will be possible in the next version of C++

result is set to 10 in the last iteration of the first for loop

and then you assign result (10) to every element of your 2-d array in the other for loops

there are numeric_limits<float>::quiet_NaN() and numeric_limits<float>::signaling_NaN()

http://en.wikipedia.org/wiki/%3F:

string is in the std namespace

if you just used pointers

#ifndef LINE_H
#define LINE_H

class Point;

class Line
{
// Ax+By+C = 0

oh my god, you are allocating one character, and then you are setting that character to the character that has the ASCII value that is the length of some other string

look at it