Pathfinder Point Buy Optimization!

scan_stats.rb

# racial bonuses and penalties to be applied, array of 
# [str, dex, con, int, wis, cha], in that order
racial_bonuses = [0, 2, -2, 2, 0, 0]
# search criteria, array of arrays, [[stat, min value], ...]
search_criteria = [[:str, 15], [:dex, 14], [:con, 14], [:int, 10], [:wis, 14]]
# the number of points available for point buy. Used exactly
points_available = 20

# determine the cost of a set
def set_cost set
  costs = { 
    10 => 0, 
    11 => 1, 
    12 => 2, 
    13 => 3, 
    14 => 5, 
    15 => 7, 
    16 => 10,
    17 => 13,
    18 => 17
  }

  set.inject 0 do |cost, i|
    cost + costs[i]
  end
end

# create an enumerator to generate stat sets with the appropriate cost
def sets_with_cost cost
  Enumerator.new do |y|
    base = (10..18).to_a
    base.each do |str|
      base.each do |dex|
        base.each do |con|
          base.each do |int|
            base.each do |wis|
              base.each do |cha|
                set = [str, dex, con, int, wis, cha]
                if set_cost(set) == cost
                  y.yield set
                end
              end
            end
          end
        end
      end
    end
  end
end

# get our enumerator
sets = sets_with_cost points_available

# apply racial bonuses
bonuses_applied = sets.collect do |set|
  set.zip(racial_bonuses).map do |a|
    a.inject { |memo, i| memo + i }
  end
end

puts "Applied bonuses to #{bonuses_applied.length} sets"

#convert updated sets into hashes on stat name
hashes = bonuses_applied.collect do |set|
  {
    :str => set[0],
    :dex => set[1],
    :con => set[2],
    :int => set[3],
    :wis => set[4],
    :cha => set[5]
  }
end

# convert search criteria into a hash (easier to read)
tagged_criteria = search_criteria.collect do |stat, value|
  { :stat => stat, :value => value }
end

# select sets based on criteria
matching_hashes = hashes.select do |hash|
  tagged_criteria.inject true do |memo, c|
    memo && (hash[c[:stat]] >= c[:value])
  end
end

puts "Found #{matching_hashes.length} sets matching criteria " +
  "#{search_criteria.collect {|stat, val| "#{stat} > #{val-1}" }.join ", "}."

# print out the set of results
matching_hashes.each do |h|
  puts h.inspect
end