Benchmarking three versions of Ruby Koans scoring algorithm

ruby_koans_scoring_benchmarks.rb

require 'benchmark'

class Gary
  # https://gist.github.com/1089115
  def score(dice)
    score_counts(dice).inject(0) {|score, pair| score + frequency_score(pair)}
  end

  def frequency_score(pair)
    triple_score(pair) + single_score(pair)
  end

  def triple_score(pair)
    (pair[:count] / 3) * triple_multiplier(pair[:score])
  end

  def triple_multiplier(score)
    score == 1 ? 1000 : score * 100
  end

  def single_score(pair)
    (pair[:count] % 3) * single_multiplier(pair[:score])
  end

  def single_multiplier(score)
    case score
    when 1; 100
    when 5; 50
    else  ; 0
    end
  end

  def score_counts(dice)
    (1..6).map do |score|
      {:score => score, :count => dice.select{|d| d == score}.size}
    end
  end
end

class Jak
  # https://gist.github.com/1088610
  def score(dice)
    score = 0
    return score if dice.empty?
    counts = [0,0,0,0,0,0]
    dice.each {|d| counts[d-1] += 1 }
    
    ones, twos, threes, fours, fives, sixes = counts

    if ones >= 3 then
      score += 1000 + ((ones-3) * 100)
    else
      score += (ones * 100)
    end 

    if fives >= 3 then
      score += 500 + ((fives-3) * 50)
    else
      score += fives * 50
    end 
    
    score += 200 if twos >= 3
    score += 300 if threes >= 3
    score += 400 if fours >= 3  
    score += 600 if sixes >= 3
    
    score
  end
end

class Serbrech
  # https://gist.github.com/906429
  def triple?(dice, val)
   dice.count {|die| die == val} >= 3
  end

  def handle_triples(dice)
    return 0 if dice.empty?
    return 350 if triple? dice, 5
    return 700 if triple? dice, 1
    return_value = 0 
    (2..6).each do |item|
      return_value = item * 100 if triple? dice, item
    end
    return return_value  
  end

  def score(dice)
    total = handle_triples dice 
    dice.each do |die|
      total += 50 if die == 5
      total += 100 if die == 1
    end
    total
  end
end

class Kevin
  # https://gist.github.com/1088913
  def score(dice)
    # Hash holds values seen in the roll and the number of duplicates for each
    h = Hash.new(0)
    dice.each { | d | h.store(d, h[d]+1) }
    
    score = 0
    
    score += h[1] * 100
    score += 700 if h[1] >= 3 # 1000 bonus points, minus the 3 * 100 points for the 1's in the set
    
    score += 200 if h[2] >= 3 
    score += 300 if h[3] >= 3
    score += 400 if h[4] >= 3
    
    score += h[5] * 50
    score += 350 if h[5] >= 3 # 500 bonus points, minus the 3 * 50 points for the 5's in the set
    
    score += 600 if h[6] >= 3
    
    score
  end
end

class Glebm
  # answer by Glebm at http://codereview.stackexchange.com/questions/423/is-this-good-ruby-ruby-koans-greed-task
  def score(dice)
    score = 0

    # Below is equivalent to:
    #   counts = dice.inject(Hash.new(0)) { |h, x| h[x] += 1; h }
    counts = Hash.new(0) 
    dice.each do |x|
      counts[x] += 1
    end

    (1..6).each do |i|
      if counts[i] >= 3 
        if i == 1
          score += 1000
        else
          score += 100 * i
        end

        counts[i] = [counts[i] - 3, 0].max
      end

      if i == 1
        score += 100 * counts[i]
      elsif i == 5
        score += 50 * counts[i]
      end
    end

    score
  end
end

class Felix
  # from Felix Alcala  http://codereview.stackexchange.com/questions/423/is-this-good-ruby-ruby-koans-greed-task 
  def score(dice)
    patterns = {[1,1,1]=>1000, [2,2,2]=>200, [3,3,3]=>300, [4,4,4]=>400,
                [5,5,5]=>500,  [6,6,6]=>600, 1=>100, 5=>50}
    sorted = dice.sort

    triple = patterns[sorted[0..2]]
    single = patterns[sorted[0]]
    if triple
      partial_score = triple
      rest = sorted[3..-1]
    elsif single
      partial_score = single
      rest = sorted[1..-1]
    else
      partial_score = 0
      rest = sorted[1..-1]
    end

    if rest
      partial_score + score(rest) 
    else
      partial_score
    end
  end
end

n = 500000
jak = Jak.new
serbrech = Serbrech.new
gary = Gary.new
kevin = Kevin.new
glebm = Glebm.new
felix = Felix.new

[[], [5], [1], [1,5,5,1], [2,3,4,6], [1,1,1]].each do |to_score|
  Benchmark.bm do |x|
    puts "Results for: " + to_score.inspect
    x.report("jak:     ") { for i in 1..n; jak.score(to_score); end }
    x.report("serbrech:") { for i in 1..n; serbrech.score(to_score); end }
    x.report("gary:    ") { for i in 1..n; gary.score(to_score); end }
    x.report("kevin:   ") { for i in 1..n; kevin.score(to_score); end }
    x.report("glebm:   ") { for i in 1..n; glebm.score(to_score); end }
    x.report("felix:   ") { for i in 1..n; felix.score(to_score); end }
    puts "-----------------------------------------------------"
  end  
end
    
 

Results from my system are:

  user     system      total        real

jak: 0.203000 0.000000 0.203000 ( 0.203021)
serbrech: 0.249000 0.000000 0.249000 ( 0.256025)
gary: 5.226000 0.000000 5.226000 ( 5.221522)
user system total real
jak: 0.562000 0.000000 0.562000 ( 0.566057)
serbrech: 1.295000 0.000000 1.295000 ( 1.293129)
gary: 5.600000 0.000000 5.600000 ( 5.607561)
user system total real
jak: 0.562000 0.000000 0.562000 ( 0.563056)
serbrech: 1.310000 0.000000 1.310000 ( 1.314132)
gary: 5.554000 0.000000 5.554000 ( 5.551555)
user system total real
jak: 0.795000 0.000000 0.795000 ( 0.802080)
serbrech: 2.309000 0.000000 2.309000 ( 2.307231)
gary: 6.614000 0.000000 6.614000 ( 6.619662)
user system total real
jak: 0.796000 0.000000 0.796000 ( 0.793079)
serbrech: 2.278000 0.000000 2.278000 ( 2.273227)
gary: 6.583000 0.000000 6.583000 ( 6.588659)
user system total real
jak: 0.733000 0.000000 0.733000 ( 0.732073)
serbrech: 0.827000 0.000000 0.827000 ( 0.820082)
gary: 6.037000 0.000000 6.037000 ( 6.044605)

Gary's version from https://gist.github.com/1089115

Serbrech's version from https://gist.github.com/906429

My version from https://gist.github.com/1088610

Was creating the object in the loop, moved that out of the loop and the differences between the three versions is even more pronounced

Added version by Kevin Pang from https://gist.github.com/1088913

Latest benchmarks are

          user     system      total        real
    jak:       0.093000   0.000000   0.093000 (  0.092009)
    serbrech:  0.141000   0.000000   0.141000 (  0.151015)
    gary:      5.117000   0.000000   5.117000 (  5.110511)
    kevin:     0.873000   0.000000   0.873000 (  0.872087)
          user     system      total        real
    jak:       0.437000   0.000000   0.437000 (  0.444044)
    serbrech:  1.170000   0.000000   1.170000 (  1.160116)
    gary:      5.538000   0.000000   5.538000 (  5.537554)
    kevin:     1.014000   0.000000   1.014000 (  1.019102)
          user     system      total        real
    jak:       0.452000   0.000000   0.452000 (  0.445044)
    serbrech:  1.155000   0.000000   1.155000 (  1.162116)
    gary:      5.429000   0.000000   5.429000 (  5.425543)
    kevin:     1.014000   0.000000   1.014000 (  1.014101)
          user     system      total        real
    jak:       0.686000   0.000000   0.686000 (  0.681068)
    serbrech:  2.168000   0.000000   2.168000 (  2.175218)
    gary:      6.537000   0.000000   6.537000 (  6.557655)
    kevin:     1.373000   0.000000   1.373000 (  1.364137)
          user     system      total        real
    jak:       0.671000   0.000000   0.671000 (  0.676067)
    serbrech:  2.137000   0.000000   2.137000 (  2.130213)
    gary:      6.505000   0.000000   6.505000 (  6.534653)
    kevin:     1.482000   0.015000   1.497000 (  1.498150)
          user     system      total        real
    jak:       0.608000   0.000000   0.608000 (  0.618062)
    serbrech:  0.702000   0.000000   0.702000 (  0.698069)
    gary:      5.944000   0.000000   5.944000 (  5.946595)
    kevin:     1.232000   0.000000   1.232000 (  1.231123)

Added two more versions, all I could find on Google, from http://codereview.stackexchange.com/questions/423/is-this-good-ruby-ruby-koans-greed-task

Thanks for posting this! Here's my version (not particularly fast). The one tiny improvement over the jak version is to put the guard clause at the very top, which shaves off a fraction for the empty case.

class Sage
  def score(dice)
    return 0 if dice.empty?
    score = 0
    # ones
    ones = dice.find_all { |x| x == 1 }
    ones_score = [0, 100, 200, 1000, 1100, 1200]
    score += ones_score[ones.count]
    # fives
    fives = dice.find_all { |x| x == 5 }
    fives_score = [0, 50, 100, 500, 550, 600]
    score += fives_score[fives.count]
    # others
    [2, 3, 4, 6].each do |y|
      y_array = dice.find_all { |x| x == y }
      if y_array.count >= 3
        score += y * 100
      end
    end
    score
  end
end