walko2.cc  From Astrachan p 331
-------------------------------
#include "walko.h"
#include "dice.h"

// part of walko.cc, just the member functions that are different
// than the functions for the class RandomWalk

RandomWalkO::RandomWalkO(WalkObserver & obs, int maxSteps)
  : myObserver(obs)
// postcondition: all private data fields initialized     
{
    myPosition = mySteps = 0;
    myMaxSteps = maxSteps;
}

void RandomWalkO::TakeStep()
// postcondition: one step of random walk taken
{
    Dice coin(2);
    switch (coin.Roll())
    {
      case 1:
        myPosition--;
        break;
      case 2:
        myPosition++;
        break;
    }
    mySteps++;

    myObserver.Update(mySteps,myPosition);
}