CSCI 150 Homework 3

Due Friday, February 14, at the beginning of class.

Goals

The goals of this assignment include:

• to play a simple game.
• to use the while statement in Pascal.

The Game of High/Low

The quizmaster chooses a number, and the guesser attempts to guess it. After each guess, the quizmaster responds with one of three responses:

Your guess is high.
Your guess is low.
Your guess is correct.  You made 5 guesses altogether.

C:\>highlow
I am thinking of a number between 0 and 20. 
Take a guess.
1
Your guess is low.
Take a guess.
13
Your guess is high.
Take a guess.
7
Your guess is low.
Take a guess.
11
Your guess is correct.  You made 4 guesses altogether.
Thanks for playing High/Low.
C:\>

Rules of the game

The quizmaster chooses a number at the beginning of the game, and doesn't change it. All the numbers are integers. The various answers the quizmaster gives must all be correct, as must the announced range. The chosen number may be at either extreme of the announced range, for example number of 20 is legal for the range between 1 and 20. The quizmaster may change ranges for each game, but is not required to do so.

Guesser

The guesser should only answer with integer numbers; for example the answer 'one' is not a legal guess. The guesser's goal is to minimize the number of guesses, so although a strategy of counting through the range is perfectly legal, it is not the best plan. The guesser may repeat guesses, even though there is no point to doing so, or may guess numbers outside the range. The responses to such silly guesses are the same as for other high or low guesses.

Pascal features

• Programs which always choose the same number, that is, don't have any mechanism for being unpredictable, will lose points.

  One way to choose a number in Pascal is used in the sample program that follows

  program choose;
  {Author: A. Professor
   Section: CSCI 150, MTR
   Date:   October 8, 2002
   Purpose: illustrate random() function.}
  var
    num:	integer;
  begin
    randomize;		{This line "shuffles" the choices -- }
  			{ otherwise they're the same every time.}
    num := random(21);    {This makes the choice. num will be between 0 and 20}
    writeln('I choose ', num); {Here we put it on the screen to show that}
  			      {the choice scheme works.}
  end.
  

• Although you could write this game with a large decision tree if you picked a range and stuck with it, programs which do so will lose points.

  I want you to have a while loop which includes statements to handle a single guess. Each guess the user makes should go through the loop again.

• You'll need several variables. These include at least:
  • A variable to keep track of the chosen number;
  • A variable to keep track of the current guess;
  • A variable to keep track of how many guesses have been made so far.
  These three are probably most appropriate as integers.

You will turn in:

1. A copy of the homework 3 cover sheet stapled to the front of the following items:
2. A listing of your program. Be sure to properly indent and comment it.
3. A printout of a run of your program.
4. A diary of your adventures in writing and debugging your program. Include mention of the people you discussed it with, the times you started, continued, and finished. Particularly write about any snags or frustrations you encountered. (You'll probably need to take notes as you go in order to remember all this detail.)
5. In addition, please email a copy of your program file, named <username>_choose.pas, as an attachment to me at croyden.mathcs.holycross.edu.