% CS99 Fall 2002
% Prelim 1
% Problem 1 
%------------------------------------------------------------------------------
% 1a [1 point]	Your lab instructor's name is GUN SRIJUNTONGSIRI.

% 1b [1 point]	Your lecture instructor's name is DAVID I. SCHWARTZ.

% 1c [1 point] 	Programming is AUTOMATING PROBLEM SOLVING.

% 1d [2 points]	MATLAB stands for MATRIX LABORATORY.

% 1e [1 point]	True or False: Everything in MATLAB is an array: TRUE.

% 1f [1 point]	True or False: 
%               The assignment statements a=10 and A=10 are identical: TRUE.

% 1g [2 points]	Demonstrate how to remove an assigned value from
%               the variable x from the command window.

  clear x % or just CLEAR

% 1h [3 points]	Show one expression statement that will evaluate:

  17 * sqrt( 2 + 3 / ( 4 - 1 ) )


% 1i [2 points]	What is the output from the following statements?
 
  x = 1; y = x + 1, z = x

  % output: y = 2
  %         z = 1


% 1j [2 points]	What is the output from the following statement?

  ~(1 ~= ~1) | 1

  % output: 1


% 1h [4 points] Write a MATLAB expression that generates a random 
%               integer between -2 and 1, inclusive.

  % formula: floor(rand*(max-min+1)) + floor(min)
  % do some arithmetic: floor(rand*(1-(-2)+1)) + floor(-2)
  
  floor(rand*4) - 2


% CS99 Fall 2002
% Prelim 1
% Problem 2
%------------------------------------------------------------------------------
% 2a Algorithm:
%    Set number of rolls so far to zero.
%    Set number of snake-eyes so far to zero.
%    If count of rolls is not exceeded (100), roll both dice.
%      + If dice1 and dice2 rolled 1, increment count of snake-eyes.
%      + Increment count of rolls.
%      + Repeat.
%    Report the number of snake-eyes out of 100 rolls.
%
% 2b Solution:

% Initialize variables:
  maxrolls = 100;  % max number of allowed rolls
  count = 0;       % number of rolls so far
  snakeeyes = 0;   % number of snake-eyes so far

% Roll both dice and count snakeeyes for maxrolls:
  for count=1:maxrolls
     count=count+1;
     roll1=floor(rand*6)+1; % roll 1st die
     roll2=floor(rand*6)+1; % roll 2nd die
     % Count snake-eyes:
       if roll1==1 & roll2==1
	 snakeeyes=snakeeyes+1;
       end
  end
  
% Report chance of rolling snake-eyes
  disp(['Chance of rolling snake-eyes: ',num2str(100*snakeeyes/maxrolls),'%']);
 
  
% CS99 Fall 2002
% Prelim 1
% Problem 3
%------------------------------------------------------------------------------

% Initialize variables:
  value1 = input('Enter a number: ');
  value2 = input('Enter another number: ');
  
% Pick max and min:
  if value1>value2
    max=value1; min=value2;
  else
    max=value2; min=value1;
  end
  
% Report even values between min and max:
  for ii=min:max
  
    % Find even number:
      if mod(ii,2)==0
	disp(num2str(ii));
      end
      
  end