about_scoring_project.rb

require File.expand_path(File.dirname(__FILE__) + '/edgecase')

# Greed is a dice game where you roll up to five dice to accumulate
# points.  The following "score" function will be used to calculate the
# score of a single roll of the dice.
#
# A greed roll is scored as follows:
#
# * A set of three ones is 1000 points
#
# * A set of three numbers (other than ones) is worth 100 times the
#   number. (e.g. three fives is 500 points).
#
# * A one (that is not part of a set of three) is worth 100 points.
#
# * A five (that is not part of a set of three) is worth 50 points.
#
# * Everything else is worth 0 points.
#
#
# Examples:
#
# score([1,1,1,5,1]) => 1150 points
# score([2,3,4,6,2]) => 0 points
# score([3,4,5,3,3]) => 350 points
# score([1,5,1,2,4]) => 250 points
#
# More scoring examples are given in the tests below:
#
# Your goal is to write the score method.

def score(dice)
  return 0 if dice == []

  return Total.single_roll(dice) if dice.count == 1

  multiples = Hash.new(0)

  dice.each do |count|
    multiples[count] += 1
  end

  score = 0
  multiples.each do |number, times|
    score += Total.multiple_roll(number, times)
  end

  return score
end


class Total
  def self.single_roll(dice)
    return 100 if dice == [1]
    return 50 if dice == [5]
    return 0 if dice != [1] || [5]
  end

  def self.multiple_roll(number, count)
    score = 0
    if count < 3 && number == 1
      score += (100 * count)
    elsif count < 3 && number == 5
      score += (50 * count)
    elsif count == 3 && number == 1
      score += 1000
    elsif count == 3 && number != 1
      score += (number * 100)
    elsif count == 4 && number == 5
      score += 550
    end
    return score
  end

end

class AboutScoringProject < EdgeCase::Koan
  def test_score_of_an_empty_list_is_zero
    #done
    assert_equal 0, score([])
  end

  def test_score_of_a_single_roll_of_5_is_50
    #done
    assert_equal 50, score([5])
  end

  def test_score_of_a_single_roll_of_1_is_100
    #done
    assert_equal 100, score([1])
  end

  def test_score_of_multiple_1s_and_5s_is_the_sum_of_individual_scores
    assert_equal 300, score([1,5,5,1])
  end

  def test_score_of_single_2s_3s_4s_and_6s_are_zero
    assert_equal 0, score([2,3,4,6])
  end

  def test_score_of_a_triple_1_is_1000
    assert_equal 1000, score([1,1,1])
  end

  def test_score_of_other_triples_is_100x
    assert_equal 200, score([2,2,2])
    assert_equal 300, score([3,3,3])
    assert_equal 400, score([4,4,4])
    assert_equal 500, score([5,5,5])
    assert_equal 600, score([6,6,6])
  end

  def test_score_of_mixed_is_sum
    assert_equal 250, score([2,5,2,2,3])
    assert_equal 550, score([5,5,5,5])
  end

end