C++ Program: Random Number Guesser.

Question

MUST HAVE TWO FILES

Submit your RandomNumberGuesser.h and RandomNumberGuesser.cpp files

Write a derived class of the NumberGuesser class named RandomNumberGuesser. The derived class should override the behavior of the getCurrentGuess method. It may also add member data and its own constructor. It may also override the higher(), lower() and reset() methods as you see fit.

To get everyone started off on the same page I have written a NumberGuesser class. It is defined entirely in-line in the following file: NumberGuesser.h (Links to an external site.)

https://fog.ccsf.edu/~mluttrel/cs110b/NumberGuesser.h

In the current NumberGuesser class the getCurrentGuess() method returns the midpoint of the range of possible values. In your RandomNumberGuesser class the getCurrentGuess() method should return a randomly generated number in the range of possible values.

Note that repeated calls to getCurrentGuess() should always return the same value for both classes if neither the higher() or the lower() functions are called. Consider the following example:



NumberGuesser *ng = new NumberGuesser(1, 10);

cout << ng->getCurrentGuess();

cout << ng->getCurrentGuess();

cout << ng->getCurrentGuess();

Each invocation of getCurrentGuess should return 5. This value does not change until the higher() or lower() function is called.

Now consider a RandomNumberGuesser example. The first call to getCurrentGuess() should return a random number between 1 and 10, inclusive. Each subsequent call to getCurrentGuess() should return the same number, until higher() or lower() is called, at which point a new random number within the new range should be generated. For example:

NumberGuesser *ng = new RandomNumberGuesser(1, 10);

// picks a random number between 1 and 10, let’s say it is 3, and outputs it.

cout << ng->getCurrentGuess();

// this line prints out 3 again, because it is still the current guess

cout << ng->getCurrentGuess();

// this line changes low to 4 because we now know the number is higher than 3.

// high remains unchanged at 10.

ng->higher();

// this line picks a random number between 4 and 10 and prints it out,

// let’s say it is 9

cout << ng->getCurrentGuess();

// this line prints out 9 again, because it is still the current guess

cout << ng->getCurrentGuess();

Make careful note of how the word “virtual” is used in NumberGuesser.h!

Answer 1

class RandomNumberGuesser : public NumberGuesser

{

protected:

int currentGuess;

bool dirtyFlag; //set when higher or lower is called

public:

RandomNumberGuesser(int l, int h) : NumberGuesser(l,h)

{

currentGuess=0;

dirtyFlag=true;

}

int getCurrentGuess()

{

if (dirtyFlag) //higher or lower has been called

{

if (high!=low)

{

srand(time(NULL));

currentGuess = rand() % (high-low) + low;

}

else

{

currentGuess = high=low;

}

dirtyFlag=false;

}

return(currentGuess);

}

void higher()

{

low = getCurrentGuess() + 1;

dirtyFlag=true;

}

void lower()

{

high = getCurrentGuess() - 1;

dirtyFlag=true;

}

};

#endif

/**************** MAIN ************************/

using namespace std;

#include <iostream>

#ifndef _RANDOM_NUMBER_GUESSER

#include "randomnumberguesser.h"

#endif

int main(int argc, char** argv)

{

RandomNumberGuesser myRandomNumberGuesser(1,10);

int magic_number=6;

int current_guess=-1;

while (current_guess != magic_number)

{

current_guess = myRandomNumberGuesser.getCurrentGuess();

cout << " the current guess is " << current_guess << endl;

cout << " I said , the current guess is " << myRandomNumberGuesser.getCurrentGuess() << endl;

cout << " One more time... the current guess is " << myRandomNumberGuesser.getCurrentGuess() << endl;

cout << "Response:" << endl;

if (magic_number>current_guess)

{

cout << "too small: guess higher " << endl;

myRandomNumberGuesser.higher();

}

else if (magic_number < current_guess)

{

cout << "too high: guess lower " << endl;

myRandomNumberGuesser.lower();

}

else

{

break;

}

cout << "-----------------------------------------" << endl;

}

if (magic_number==current_guess)

{

cout << " Congratulations... " << magic_number << " : " << current_guess << endl;

}

return 0;

}