c++ skip list implementation?

[Lindley]

First thing: Since your classes use "new" in the constructor (and presumably "delete" in the destructor), you have to make sure they either have valid copy semantics, or else cannot be copied. The latter is easier in most cases. Simply add this to the class definition:

private:
    void operator=(const classname & rhs);
    classname(const classname & original);

If that produces any errors, then it signifies a problem with your usage: Either you'll need to stop trying to make whatever copy you're making, or you'll need to actually define both of those functions.