walko.h  From Astrachan p. 326-327
----------------------------------
#ifndef _RANDOMWALKO_H
#define _RANDOMWALKO_H

// Owen Astrachan, 6/20/96
// class for implementing a one dimensional random walk with observer
//
// constructor specifies observer and number of steps to take, random walk
// goes left or right with equal probability, updating the observer
// with each step
//
// two methods for running simulation:
//
// void Simulate()  -- run a complete simulation
//
// First(); ! IsDone(); Next() -- idiom for starting and iterating
//                                one step at a time
//
// accessor functions:
//
// int GetPosition() -- returns x coordinate
//                      (# steps left/right from origin)
//
// int GetSteps()    -- returns total # steps taken

#include "observer.h"

class RandomWalkO
{
  public:
    RandomWalkO(WalkObserver & obs,
                int maxSteps); // constructor, set observer and max steps
    void First();              // take first step of walk
    bool IsDone();             // returns true if walk finished, else false
    void Next();               // take next step of random walk
    
    void Simulate();           // take all steps in simulation
    
    int GetPosition();         // returns position (x coord) of frog
    int GetSteps();            // returns # of steps taken by frog
  private:
    void TakeStep();           // simulate one step of walk
    int myPosition;            // current x coordinate
    int mySteps;               // # of steps taken
    int myMaxSteps;            // maximum # of steps allowed

    WalkObserver& myObserver;  // observe this walk
};

#endif