5mkn.rb

#!/usr/bin/env ruby

class AlreadyExistsStone < StandardError; end

def init_board(num = 19)
  @board = Array.new(num){ Array.new(num) }
end

def init_narabe(num = 5)
  @narabe = num
end

def init_stone
  @stone = :black
end

def change_stone
  @stone = @stone.eql?(:black) ? :white : :black
end

def show_board
  puts @board.inspect
end

def show_next_stone
  puts "next -> #{@stone.to_s}"
end

def parse_stdin
  gets.chomp.split(' ').map {|str| str.to_i - 1 }
end

def put_stone(pos)
  res = @board[pos.first][pos.last]
  if res.nil?
    @board[pos.first][pos.last] = @stone
  else
    raise AlreadyExistsStone
  end
end

def finish?
  check_horizon(@board)
  check_horizon(@board.transpose)
  check_slanting(@board)
  check_slanting(@board.transpose)
end

def check_horizon(board)
  continuing = 0
  board.each do |arr|
    arr.each do |square|
      if square == @stone
        continuing += 1
      else
        continuing = 0
      end
      return true if continuing == @narabe
    end
  end

  false
end

def check_slanting(board)
  continuing = 0

  # TODO
  false
end

def main
  loop do
    begin
      show_next_stone
      put_stone(parse_stdin)
      change_stone
      show_board
      finish?
    rescue
      # TODO: error message
      retry
    end
  end
end

def prepare
  init_board
  init_narabe
  init_stone
end

prepare
main