converting a coin flip bet int oa bet on a house race game

You recently won $50 in a raffle. Instead of putting it in the bank like you know you should, you decide to go down to the racetrack and see how many races your money can last. The race track has horse races all summer long with each race consisting of 5 horses. You must wager $10 on each race. The horses with the highest chance of winning will always have lower payouts, while the horses with the lowest chance of winning will always have the highest payouts.

Assume the following conditions are true for all races:

• The horse in gate 1 will always have a 16% of winning and a payout of $35.
• The horse in gate 2 will always have a 20% of winning and a payout of $30.
• The horse in gate 3 will always have a 28% of winning and a payout of $20.
• The horse in gate 4 will always have a 24% of winning and a payout of $25.
• The horse in gate 5 will always have a 12% of winning and a payout of $40.Write a MATLAB program that will ask for the user to pick a horse (1, 2, 3, 4, or 5) and then will use the “rand” or “randi” command to determine the winner of the race. After each race, the program will:

1) Adjust the total money accordingly (deduct bet, add payout)

2) Display the balance to the user

3) Ask the user to pick a new horse

4) Continue with the next race with a new random number determining the winning horse

This will continue until a balance of under $10 is reached. When a balance under $10 is reached, have MATLAB output to the user:

1) How many races their money lasted and

2) The maximum possible they could have won if they guessed correctly every time

cash=20;
maxcash=0;
attempts=0;
disp('So you''ve got $20 and you''re a betting man/woman?')
disp(' ')
disp('Tell you what - I''ll flip a coin and you guess heads or tails.')
disp(' ')
disp('If you guess right, I''ll give you $5.')
disp('If you guess wrong, I''ll take your $5.')
disp(' ')
disp('Let''s begin!')
disp(' ')
disp(' ')
%To flip a coin, say 1=heads and 2=tails, ask the user to guess:
guess=input('Please guess heads (1) or tails (2) for random coin flip: ');

%I want the code to iterate and let the user keep playing until they run
%out of money or quit:
while cash>=5      %We'll say it's $5 to bet each time
    clc
    cash=cash-5;       %Take out $5 for starting bet
    chance=randi(2);      %Chance is either 1 or 2, 50% even chance for either
    %chance=rand         %Chance is a random number between 0 and 1
    attempts=attempts+1;
    if chance==1        %Hitting heads
        flip=1;
    elseif chance==2
        flip=2; 
    end
    if flip==guess       %User guesses correctly
        if flip==1        %Hitting heads
            cash=cash+10;    %They double their bet if they win
        elseif flip==2      %Hitting tails
            cash=cash+10;    %Same as above
        end
        disp('Congrats, you guessed it!')
        disp(['Your new cash total is $' num2str(cash) '!'])
    elseif guess<1 || guess>2
        disp('You didn''t follow instructions...')
        disp('Thanks for the $5 donation!')
        disp(['Your new cash total is $' num2str(cash) '!'])
    else
        disp('Sorry, you guessed incorrectly.. =(')
        disp(['Your new cash total is $' num2str(cash) '!'])
    end
    if flip==1          %This if loop to capture max possible amount you could win
        maxcash=maxcash+5;
    elseif flip==2
        maxcash=maxcash+5;     
    end
    if cash>=5             %This IF loop will cancel prompting the user if they run out of money
        disp('Please guess again for the next coin flip.')
        guess=input('Put 1 for heads and 2 for tails: ');
    end
end
        
%I want to display the result to the user:
disp(' ')
disp(['You made it for ' num2str(attempts) ' coin flips.'])
disp(' ')
disp(['The maximum you could have possibly won is:'])
disp(['$',num2str(maxcash)])

[Image Analyst]

I see you've posted your stated question (probably from a homework assignment), and your code for doing as the question instructed. But so what? Do you have a question for us? If so, you forgot to post it.

[Todd Wyzkiewicz]

Yes, that was my bad. My question was how to actually change this code to work the is implent? I don't really mean that to be as broud as that sounds, but I'm unsure how to go about changing the 2 veriables into 5. What I tried at first was just changing the numbers and adding more (if)'s to the while loops, but that dosn't work and is overly comlicaded. another question of mine is how to assingn the persentages and dollar amounts to the variablies if the user was to get the get a quess right?

[Todd Wyzkiewicz]

The code is mine for a previous assignment.The instructor has said in his notes to use this one and not much has to be changed, but I don't see much of a corralation between the two.

Answer 1

[Image Analyst]

Here is a hint. This will let you see how you can use cumsum() and rand() to get the correct probability for each lane to win.

percentages = [0.16, 0.2, 0.28, 0.24, 0.12];
theSum = cumsum(percentages)
% Run 3000 races
numRaces = 3000;
horseHistogram = zeros(1, length(percentages)); % 5 bin histogram.
for race = 1 : numRaces
	randomNumber = rand(1);
	if randomNumber <= theSum(1)
		% Horse #1 won
		winningHorse = 1;
	elseif randomNumber <= theSum(2)
		% Horse #2 won
		winningHorse = 2;
	elseif randomNumber <= theSum(3)
		% Horse #3 won
		winningHorse = 3;
	elseif randomNumber <= theSum(4)
		% Horse #4 won
		winningHorse = 4;
	else
		% Horse #5 won
		winningHorse = 5;
	end
	horseHistogram(winningHorse) = horseHistogram(winningHorse) + 1;
end
for h = 1 : length(horseHistogram)
	fprintf('Horse %d won %0.3f %% of the time.\n', h, 100 * horseHistogram(h) / numRaces);
end

theSum =

0.16 0.36 0.64 0.88 1

Horse 1 won 15.400 % of the time.

Horse 2 won 21.333 % of the time.

Horse 3 won 28.133 % of the time.

Horse 4 won 23.267 % of the time.

Horse 5 won 11.867 % of the time.

Just the percentages you'd expect.

Adapt as needed. You'll need to convert the for loop to a while loop

while cashRemaining >= 10

Then adjust cashRemaining based on loss or winnings for that race.

[Todd Wyzkiewicz]

Thank you for that much it did get me in the right dirction, but what would I have to do to this do make the code run again if the user was to input the wrong answer? So the game can would carry on until they got it right once or stop if they run out of money.

[Todd Wyzkiewicz]

I know its a while loop that needs to be made and thanks for the hint, but but its just give me errors becuse the formates wrong.

Would it work if I tried to made the while loop seprate and have that hanlde the money protion of the code?

clear
clc

cash=20;
maxcash=50;
attempts=0;
disp('So you''ve got $50 that you won from a bet?')
disp(' ')
disp('lets see how lucky you really are.')
disp('The race starts soon so Let''s get it!')
disp(' ')
%idenifing what gate the user is betting on.
guess=input('Please guess the winning horse. Out of 5 gates what horse are you betting on: ');

percentages = [0.16, 0.2, 0.28, 0.24, 0.12];
theSum = cumsum(percentages);
% Run 3000 races
numRaces = 3000;
horseHistogram = zeros(1, length(percentages)); % 5 bin histogram.

% while maxcash <= 10

for race = 1 : numRaces
	randomNumber = rand(1);
    attempts = attempts+1;
	if randomNumber <= theSum(1)
		% Horse #1 won
		winningHorse = 1;
%         maxcash = maxcash + 35;
	elseif randomNumber <= theSum(2)
		% Horse #2 won
		winningHorse = 2;
%         maxcash = maxcash +30;
	elseif randomNumber <= theSum(3)
		% Horse #3 won
		winningHorse = 3;
%         maxcash = maxcash +25;
	elseif randomNumber <= theSum(4)
		% Horse #4 won
		winningHorse = 4;
%         maxcash = maxcash +20;
	else
		% Horse #5 won
		winningHorse = 5;
%         maxcash = maxcash +40;
	end
	horseHistogram(winningHorse) = horseHistogram(winningHorse) + 1;
end

while maxcash<= 10

    if  
    
end
% end
for h = 1 : length(horseHistogram)
	fprintf('Horse %d won %0.3f %% of the time.\n', h, 100 * horseHistogram(h) / numRaces);
end
        
        
%I want to display the result to the user:
disp(' ')
disp(['Horse ' (num2str(winningHorse)) ' won this race'])
disp(' ')
disp(['The maximum you could have possibly won is:'])
disp(['$',num2str(maxcash)])

[Image Analyst]

You need to put all that race stuff inside the while loop, not before it. And get rid of the for loop like I told you - you need to have it be the while:

clc;    % Clear the command window.
fprintf('Beginning to run %s.m.\n', mfilename);
close all;  % Close all figures (except those of imtool.)
clearvars;  % Erase all existing variables.
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 20;

startingCash = 50;
currentCash = startingCash;
numberOfRaces = 0;
fprintf('You are starting with $%d.\n\n', startingCash)
disp('Let''s see how lucky you really are.')
disp('The race starts soon so Let''s get it!')
disp(' ')

payouts = [35, 30, 20, 25, 40];
percentages = [0.16, 0.2, 0.28, 0.24, 0.12];
theSum = cumsum(percentages);
horseHistogram = zeros(1, length(percentages)); % 5 bin histogram.

while currentCash >= 10
	numberOfRaces = numberOfRaces + 1;
	% Ask user what horse/gate they are betting on.
	userPrompt = sprintf('Please guess the winning horse for race #%d. Out of 5 gates what horse are you betting on: ', numberOfRaces);
	guessedHorse = input(userPrompt);
	% Make a bet of exactly $10.
	currentCash = currentCash - 10;
	
	% Now run the race.
	randomNumber = rand(1);
	if randomNumber <= theSum(1)
		% Horse #1 won
		winningHorse = 1;
	elseif randomNumber <= theSum(2)
		% Horse #2 won
		winningHorse = 2;
	elseif randomNumber <= theSum(3)
		% Horse #3 won
		winningHorse = 3;
	elseif randomNumber <= theSum(4)
		% Horse #4 won
		winningHorse = 4;
	else
		% Horse #5 won
		winningHorse = 5;
	end
	horseHistogram(winningHorse) = horseHistogram(winningHorse) + 1;
	fprintf('Horse %d won this race, and %0.3f %% of the prior races.\n', winningHorse, 100 * horseHistogram(winningHorse) / numberOfRaces);
	
	% See if they won
	if guessedHorse == winningHorse
		% They won.  Add their winnings to the current cash.
		currentCash = currentCash + payouts(winningHorse);
		fprintf('YOU WON $%d on this race.\n', payouts(winningHorse));
	else
		fprintf('YOU LOST $10 on this race because you bet on horse %d while horse %d actually won the race.\n', guessedHorse, winningHorse);
	end
	% Let them know how much cash they have left:
	fprintf('After %d races, you have $%d left\n\n', numberOfRaces, currentCash);
end
fprintf('At the end of the day, after %d races, you have $%d left and you cannot bet again.\n', numberOfRaces, currentCash);

[Todd Wyzkiewicz]

WOW! Thank you. I was really strugling with this and probably would have taking week for me to get all of that done. Thanks again and keep doing what you're doing!