Lab 2: Scrabble
Labs are practice problems which, time permitting, may be started or completed in your section, and are assessed on correctness only. You are encouraged to collaborate with classmates on this lab, though each member in a group collaborating is expected to contribute equally to the lab.
Determine which of two Scrabble words is worth more.
$ ./scrabble
Player 1: COMPUTER
Player 2: science
Player 1 wins!
Getting Started
Open VS Code.
Start by clicking inside your terminal window, then execute cd
by itself. You should find that its “prompt” resembles the below.
$
Click inside of that terminal window and then execute
wget https://cdn.cs50.net/2021/fall/labs/2/scrabble.zip
followed by Enter in order to download a ZIP called scrabble.zip
in your codespace. Take care not to overlook the space between wget
and the following URL, or any other character for that matter!
Now execute
unzip scrabble.zip
to create a folder called scrabble
. You no longer need the ZIP file, so you can execute
rm scrabble.zip
and respond with “y” followed by Enter at the prompt to remove the ZIP file you downloaded.
Now type
cd scrabble
followed by Enter to move yourself into (i.e., open) that directory. Your prompt should now resemble the below.
scrabble/ $
If all was successful, you should execute
ls
and you should see a file called scrabble.c
. Open that file by executing the below:
code scrabble.c
If you run into any trouble, follow these same steps steps again and see if you can determine where you went wrong!
Background
In the game of Scrabble, players create words to score points, and the number of points is the sum of the point values of each letter in the word.
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | 3 | 3 | 2 | 1 | 4 | 2 | 4 | 1 | 8 | 5 | 1 | 3 | 1 | 1 | 3 | 10 | 1 | 1 | 1 | 1 | 4 | 4 | 8 | 4 | 10 |
For example, if we wanted to score the word Code
, we would note that in general Scrabble rules, the C
is worth 3
points, the o
is worth 1
point, the d
is worth 2
points, and the e
is worth 1
point. Summing these, we get that Code
is worth 3 + 1 + 2 + 1 = 7
points.
Implementation Details
Complete the implementation of scrabble.c
, such that it determines the winner of a short scrabble-like game, where two players each enter their word, and the higher scoring player wins.
- Notice that we’ve stored the point values of each letter of the alphabet in an integer array named
POINTS
.- For example,
A
ora
is worth 1 point (represented byPOINTS[0]
),B
orb
is worth 3 points (represented byPOINTS[1]
), etc.
- For example,
- Notice that we’ve created a prototype for a helper function called
compute_score()
that takes a string as input and returns anint
. Whenever we would like to assign point values to a particular word, we can call this function. Note that this prototype is required for C to know thatcompute_score()
exists later in the program. - In
main()
, the program prompts the two players for their words using theget_string()
function. These values are stored inside variables namedword1
andword2
. - In
compute_score()
, your program should compute, using thePOINTS
array, and return the score for the string argument. Characters that are not letters should be given zero points, and uppercase and lowercase letters should be given the same point values.- For example,
!
is worth0
points whileA
anda
are both worth1
point. - Though Scrabble rules normally require that a word be in the dictionary, no need to check for that in this problem!
- For example,
- In
main()
, your program should print, depending on the players’ scores,Player 1 wins!
,Player 2 wins!
, orTie!
.
Walkthrough
This video was recorded when the course was still using CS50 IDE for writing code. Though the interface may look different from your codespace, the behavior of the two environments should be largely similar!
Hints
-
You may find the functions
isupper()
andislower()
to be helpful to you. These functions take in a character as the argument and return a boolean. -
To find the value at the
n
th index of an array calledarr
, we can writearr[n]
. We can apply this to strings as well, as strings are arrays of characters. -
Recall that computers represent characters using ASCII, a standard that represents each character as a number.
Not sure how to solve?
How to Test Your Code
Your program should behave per the examples below.
$ ./scrabble
Player 1: Question?
Player 2: Question!
Tie!
$ ./scrabble
Player 1: Oh,
Player 2: hai!
Player 2 wins!
$ ./scrabble
Player 1: COMPUTER
Player 2: science
Player 1 wins!
$ ./scrabble
Player 1: Scrabble
Player 2: wiNNeR
Player 1 wins!
Execute the below to evaluate the correctness of your code using check50
. But be sure to compile and test it yourself as well!
check50 cs50/labs/2022/spring/scrabble
Execute the below to evaluate the style of your code using style50
.
style50 scrabble.c
How to Submit
- Download your
scrabble.c
file by control-clicking or right-clicking on the file in your codespace’s file browser and choosing Download. - Go to CS50’s Gradescope page.
- Click “Lab 2: Scrabble”.
- Drag and drop your
scrabble.c
file to the area that says “Drag & Drop”. Be sure it has that exact filename! If you upload a file with a different name, the autograder likely will fail when trying to run it, and ensuring you have uploaded files with the correct filename is your responsibility! - Click “Upload”.
You should see a message that says “Lab 2: Scrabble submitted successfully!”