Lab 2: Scrabble

Determine which of two Scrabble words is worth more.

$ ./scrabble
Player 1: COMPUTER
Player 2: science
Player 1 wins!


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.

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.

Getting Started

  • Copy the “distribution code” (i.e., starter code) from into a new file in your IDE called scrabble.c.
    • You can also download the distribution code by running the command wget in CS50 IDE.

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 or a is worth 1 point (represented by POINTS[0]), B or b is worth 3 points (represented by POINTS[1]), etc.
  • Notice that we’ve created a prototype for a helper function called compute_score() that takes a string as input and returns an int. 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 that compute_score() exists later in the program.
  • In main(), the program prompts the two players for their words using the get_string() function. These values are stored inside variables named word1 and word2.
  • In compute_score(), your program should compute, using the POINTS 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 worth 0 points while A and a are both worth 1 point.
    • Though Scrabble rules normally require that a word be in the dictionary, no need to check for that in this problem!
  • In main(), your program should print, depending on the players’ scores, Player 1 wins!, Player 2 wins!, or Tie!.


  • You may find the functions isupper() and islower() to be helpful to you. These functions take in a character as the argument and return a boolean.

  • To find the value at the nth index of an array called arr, we can write arr[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.

How to Test Your Code

Your program should behave per the examples below.

$ ./scrabble
Player 1: Question?
Player 2: Question!
$ ./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/2020/fall/scrabble

Execute the below to evaluate the style of your code using style50.

style50 scrabble.c

How to Submit

  1. Download your scrabble.c file by control-clicking or right-clicking on the file in CS50 IDE’s file browser and choosing Download.
  2. Go to CS50’s Gradescope page.
  3. Click “Lab 2: Scrabble”.
  4. Drag and drop your scrabble.c file to the area that says “Drag & Drop”. Be sure it has the correct filename!
  5. Click “Upload”.

You should see a message that says “Lab 2: Scrabble submitted successfully!”