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alexwebgr's solution

to Scrabble Score in the Ruby Track

Published at Feb 14 2021 · 0 comments
Instructions
Test suite
Solution

Given a word, compute the scrabble score for that word.

Letter Values

You'll need these:

Letter                           Value
A, E, I, O, U, L, N, R, S, T       1
D, G                               2
B, C, M, P                         3
F, H, V, W, Y                      4
K                                  5
J, X                               8
Q, Z                               10

Examples

"cabbage" should be scored as worth 14 points:

  • 3 points for C
  • 1 point for A, twice
  • 3 points for B, twice
  • 2 points for G
  • 1 point for E

And to total:

  • 3 + 2*1 + 2*3 + 2 + 1
  • = 3 + 2 + 6 + 3
  • = 5 + 9
  • = 14

Extensions

  • You can play a double or a triple letter.
  • You can play a double or a triple word.

For installation and learning resources, refer to the Ruby resources page.

For running the tests provided, you will need the Minitest gem. Open a terminal window and run the following command to install minitest:

gem install minitest

If you would like color output, you can require 'minitest/pride' in the test file, or note the alternative instruction, below, for running the test file.

Run the tests from the exercise directory using the following command:

ruby scrabble_score_test.rb

To include color from the command line:

ruby -r minitest/pride scrabble_score_test.rb

Source

Inspired by the Extreme Startup game https://github.com/rchatley/extreme_startup

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

scrabble_score_test.rb

require 'minitest/autorun'
require_relative 'scrabble_score'

class ScrabbleTest < Minitest::Test
  def test_empty_word_scores_zero
    assert_equal 0, Scrabble.new('').score
  end

  def test_whitespace_scores_zero
    skip
    assert_equal 0, Scrabble.new(" \t\n").score
  end

  def test_nil_scores_zero
    skip
    assert_equal 0, Scrabble.new(nil).score
  end

  def test_scores_very_short_word
    skip
    assert_equal 1, Scrabble.new('a').score
  end

  def test_scores_other_very_short_word
    skip
    assert_equal 4, Scrabble.new('f').score
  end

  def test_simple_word_scores_the_number_of_letters
    skip
    assert_equal 6, Scrabble.new('street').score
  end

  def test_complicated_word_scores_more
    skip
    assert_equal 22, Scrabble.new('quirky').score
  end

  def test_scores_are_case_insensitive
    skip
    assert_equal 41, Scrabble.new('OXYPHENBUTAZONE').score
  end

  def test_convenient_scoring
    skip
    assert_equal 13, Scrabble.score('alacrity')
  end
end

scrabble_score.rb

class Scrabble
  TILE_SET = {
    "A" => 1, "N" => 1,
    "B" => 3, "O" => 1,
    "C" => 3, "P" => 3,
    "D" => 2, "Q" => 10,
    "E" => 1, "R" => 1,
    "F" => 4, "S" => 1,
    "G" => 2, "T" => 1,
    "H" => 4, "U" => 1,
    "I" => 1, "V" => 4,
    "J" => 8, "W" => 4,
    "K" => 5, "X" => 8,
    "L" => 1, "Y" => 4,
    "M" => 3, "Z" => 10
  }

  def self.score(word)
    new(word).score
  end

  private

  attr_reader :word
  attr_reader :tile_set

  def initialize(word, tile_set = TILE_SET)
    @word = word.to_s.gsub(/[^a-zA-Z]/, '').upcase
    @tile_set = tile_set
  end

  public

  def score
    return 0 if word.empty?

    word.chars.tally.sum do |letter|
      tile_set[letter[0]] * letter[1]
    end
  end
end

scrabble_score_guard.rb

require './ruby/scrabble-score/scrabble_score'

if $PROGRAM_NAME == __FILE__
  hawaiian = {
    "A" => 1,
    "N" => 3,
    "O" => 2,
    "P" => 8,
    "E" => 4,
    "H" => 6,
    "U" => 5,
    "I" => 3,
    "W" => 9,
    "K" => 2,
    "L" => 7,
    "M" => 8,
    "‘" => 0 # I don't know the score for this letter. I think it might be 0
  }

  puts Scrabble.new('hello').score # 8
  puts Scrabble.new('aloha', tile_set = hawaiian).score # 17
  puts Scrabble.new('aloha', hawaiian).score # 17
  puts Scrabble.new('he‘e', hawaiian).score # => 14
  puts Scrabble.new('Humuhumunukunukuapuaa', hawaiian).score # 94
end

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