Generally fairly good solutions to the problem but with some sloppiness in lots of code. Specific problems which cropped up recurrently were lack of use of consts, not checking for divide by zero, forgetting to implement destructor, copy constructor and assignment operator in heap implementation. Also not many people added useful extra functionality such as output operators (the spec say the class must AT LEAST implement the functionality described. Those who went further and implemented an equality operator generally produced a buggy implementation that made an == test between doubles - not very reliable. Testing was generally good but the discussion of performance enhancements (implemented or envisaged) was frequently absent.