triangle puzzle solver

TrianglePuzzleSolver.rb

#!/usr/bin/env ruby
# -*- coding: utf-8 -*-

# TrianglePuzzleSolver.rb
#   by takehikom

# inspired by:
# http://www.huffingtonpost.jp/satoshi-kagimoto/triangle-puzzle_b_5590269.html

module TrianglePuzzle
  class Table
    def initialize(ary)
      @array = ary.dup
    end
    attr_accessor :array

    def print_table(flag_sum = false)
      puts "   #{@array[9]}"
      puts "  #{@array[7]} #{@array[8]}"
      puts " #{@array[4]} #{@array[5]} #{@array[6]}"
      puts "#{@array[0]} #{@array[1]} #{@array[2]} #{@array[3]}"

      if flag_sum
        a = get_six_sums
        puts "left[1]  = #{a.shift}"
        puts "left[2]  = #{a.shift}"
        puts "down[1]  = #{a.shift}"
        puts "down[2]  = #{a.shift}"
        puts "right[1] = #{a.shift}"
        puts "right[2] = #{a.shift}"
      end
    end

    def get_six_sums
      [@array[7] + @array[8],
        @array[4] + @array[5] + @array[6],
        @array[4] + @array[1],
        @array[7] + @array[5] + @array[2],
        @array[8] + @array[5] + @array[1],
        @array[6] + @array[2]]
    end
    alias :sums :get_six_sums

    def valid?(flag_msg = false)
      if @array.length != 10
        flag_msg ? "wrong size" : false
      elsif @array.map {|item| [1, 2, 3, 4, 5].index(item).nil?}.uniq != [false]
        flag_msg ? "invalid value" : false
      elsif @array.values_at(0, 1, 2, 3, 5).sort != [1, 2, 3, 4, 5] ||
          @array.values_at(0, 4, 5, 7, 9).sort != [1, 2, 3, 4, 5] ||
          @array.values_at(3, 5, 6, 8, 9).sort != [1, 2, 3, 4, 5]
        flag_msg ? "wrong permutation" : false
      else
        flag_msg ? "OK" : true
      end
    end
  end

  class Searcher
    def initialize; end
    attr_reader :all, :hash

    def start(flag_print = false)
      @all = []
      @hash = Hash.new
      tab_cnt = 0

      [1, 2, 3, 4, 5].permutation do |a|
        ary = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
        ary[0] = a[0]
        ary[1] = a[1]
        ary[2] = a[2]
        ary[3] = a[3]
        ary[5] = a[4]

        ([1, 2, 3, 4, 5] - [ary[0], ary[3], ary[5]]).each do |b|
          ary[9] = b

          ([1, 2, 3, 4, 5] - [ary[0], ary[5], ary[9]]).permutation do |c|
            ary[4] = c[0]
            ary[7] = c[1]

            ([1, 2, 3, 4, 5] - [ary[3], ary[5], ary[9]]).permutation do |d|
              ary[6] = d[0]
              ary[8] = d[1]

              tab = TrianglePuzzle::Table.new(ary)
              # tab.valid? || raise

              tab_cnt += 1
              if flag_print
                puts "==== Table #{tab_cnt} ===="
                tab.print_table
                puts "sums: #{tab.get_six_sums.join(', ')}"
                puts
              end
              @all << ary
              k = tab.get_six_sums.join(",")
              if @hash.key?(k)
                @hash[k] << tab
              else
                @hash[k] = [tab]
              end
            end
          end
        end
      end
    end
  end
end

if __FILE__ == $0
  s = TrianglePuzzle::Searcher.new
  s.start($DEBUG)

  puts "==== 10,7,7,9,11,7 ===="
  s.hash["10,7,7,9,11,7"].each do |tab|
    tab.print_table(true)
  end
  puts

  puts "==== 6,11,6,8,6,7 ===="
  s.hash["6,11,6,8,6,7"].each do |tab|
    tab.print_table(true)
  end
  puts

  if $DEBUG
    h = s.hash
    h.keys.sort_by {|item| item.split(/,/).map {|num| num.to_i}}.each do |k|
      puts "====== values=#{k} ======"
      h[k].each_with_index do |tab, i|
        puts "(case #{i + 1})"
        tab.print_table(true)
      end
      puts
    end
  end
end