colinwarmstrong / scrabble

Timed code challenge implementing a scoring system for the board game Scrabble using Ruby.

Scrabble

Work on the sample exercise defined below for 2 hours.

As you work, you may:

• Ask clarifying questions of your facilitator
• Reference external public resources (ie: Google, Ruby API, etc)
• Use the tooling most comfortable to you (Editor/IDE, testing framework, support tools like Guard, etc)

As you work, you should not:

• Copy code snippets other than those present in this description
• Seek live support from individuals other than your facilitator
• Use past projects to use as guides/examples

Preparation

1. Fork this repository.
2. Clone your new repository to your local machine ($ git clone https://github.com/<YOUR GITHUB USERNAME>/scrabble.git)
3. cd into your scrabble directory.
4. Run bundle from the command line.
5. Run rake from the command line.

Running Specs/Tests

To run the MiniTest tests run rake from the command line.

Overview

Let’s use test-driven development to build pieces of a Scrabble-like game.

At a high level, you will be adding to an existing Scrabble class to make it so that it can score words. Words will be scored based on the following letter values:

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

Or, stored as a Ruby hash:

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

}

When complete, your Scrabble class will be able to:

1. score a word,
2. score an empty string,
3. score when someone passes nil
4. score a word with letter multipliers,
5. score word with a word multiplier,
6. score a word with a seven-letter bonus.

Interaction Pattern

Using test-driven development, implement an interaction pattern that scores words insensitive to case, such that an empty word or nil scores 0, which follows the interaction pattern below.

> game = Scrabble.new
=> ...
> game.score("hello")
=> 8
> game.score("")
=> 0
> game.score(nil)
=> 0

Note: a double letter score in Scrabble is dependent on the position of a letter on the board. The arrays passed to #score_with_multipliers below indicate the multiplier for a letter in the corresponding position of the word that is passed as the first argument.

> game.score_with_multipliers('hello', [1,2,1,1,1])
=> 9
> game.score_with_multipliers('hello', [1,2,1,1,1], 2)
=> 18

Additionally, a word scores a 10-point bonus (applied before the word multiplier) if that word has seven or more letters.

> game.score_with_multipliers('sparkle', [1,2,1,3,1,2,1], 2)
=> 58

Use the existing point_values method in the Scrabble class as a source for each letter's value.

It is expected that you will add to the existing tests in test/scrabble_test.rb.

BONUS

Highest Scoring Word

Implement a highest_scoring_word method that works like the examples below.

game = Scrabble.new
game.highest_scoring_word(['home', 'word', 'hello', 'sound'])  # => "home"

Note that it's better to use fewer tiles, so if the top score is tied between multiple words, pick the one with the fewest letters:

game = Scrabble.new
game.highest_scoring_word(['hello', 'word', 'sound'])  # => "word"

But there is a bonus for using all seven letters. If one of the highest scores uses all seven letters, pick that one:

game = Scrabble.new
game.highest_scoring_word(['home', 'word', 'silence'])  # => "silence"

But if the there are multiple words that are the same score and same length, pick the first one in supplied list:

game = Scrabble.new
game.highest_scoring_word(['hi', 'word', 'ward'])  # => "word"

Reading Game Data

Find a file named input.csv in the ./test/ folder with this game data:

player_id,word
1,hello
2,hi
1,silence
2,snacker
1,fun

Write code that can parse that file and follow this interaction pattern:

game = GameReader.new('./test/input.csv')
game.word_count(:player_1)  # => 3
game.word_count(:player_2)  # => 2
game.score(:player_1)       # => 23
game.score(:player_2)       # => 18