29 The Power of Inheritance and Polymorphism

WindowRep and Window classes 102929.2.3 DungeonItem hierarchyClass Monster is meant to be an abstraction; the real inhabitants of the dungeon areinstances of specialized subclasses of class Monster.Class Monster has to provide the following functions (there may be othersfunctions, and the work done in these functions may get expanded later, this listrepresents an initial guess):• Constructor and destructorThe constructor will set a Dungeon* pointer to link back to the Dungeon objectand set a char data member to the symbol used to represent the Monster on themap view.Since class Monster is to be in a hierarchy, it had better define a virtualdestructor.• ReadA Monster is supposed to read details of its initial position, its "health" and"strength" from an input file. It will need data members to store thisinformation.• Access functions to get position, to check whether "alive", …• A Run() function that as already outlined will work through redefinableauxiliary functions like CanAttack(), Attack(), CanDetect(), Advance()and NormalMove().• Draw and Erase functions.• A Move function.Calls Erase(), changes coords to new coords given as argument, and callsDraw().• GetHit functionReduces "health" attribute in accord with damage inflicted by Player.The example implementation has three specializations: Ghost, Patrol, andWanderer. These classes redefine member functions from class Monster asneeded.A Ghost is a Monster that:class Ghost• uses the default "do nothing" implementation defined by Monster::NormalMove() along with the standard CanAttack(), Attack() functions;• has a CanDetect() function that returns true when the player is within a fixeddistance of the point where the Ghost is located (the presence of interveningwalls makes no difference to a Ghost object's power of detection);