# -*- coding: utf-8 -*-
class Array

  def point(x, y)
    self[y][x]
  end

  def set_point(x, y, char)
    self[y][x] = char
    self
  end

  def find_zero
    each_with_index do |ary, y|
      x = ary.find_index '0'
      if x
        return [x, y]
      end
    end
  end

  def find_char(char)
    each_with_index do |ary, y|
      x = ary.find_index char
      if x
        return [x, y]
      end
    end
    nil
  end

  def up
    zero_x, zero_y = find_zero
    return false if zero_y == 0
    char = point(zero_x, zero_y - 1)
    return false if char == '='
    ary = Marshal.load(Marshal.dump(self))
    ary.set_point(zero_x, zero_y, char)
    ary.set_point(zero_x, zero_y - 1, '0')
    ary
  end

  def down
    zero_x, zero_y = find_zero
    return false if zero_y >= self.size - 1
    char = point(zero_x, zero_y + 1)
    return false if char == '='
    ary = Marshal.load(Marshal.dump(self))
    ary.set_point(zero_x, zero_y, char)
    ary.set_point(zero_x, zero_y + 1, '0')
    ary
  end

  def right
    zero_x, zero_y = find_zero
    return false if zero_x >= self.first.size - 1
    char = point(zero_x + 1, zero_y)
    return false if char == '='
    ary = Marshal.load(Marshal.dump(self))
    ary.set_point(zero_x, zero_y, char)
    ary.set_point(zero_x + 1, zero_y, '0')
    ary
  end

  def left
    zero_x, zero_y = find_zero
    return false if zero_x == 0
    char = point(zero_x - 1, zero_y)
    return false if char == '='
    ary = Marshal.load(Marshal.dump(self))
    ary.set_point(zero_x, zero_y, char)
    ary.set_point(zero_x - 1, zero_y, '0')
    ary
  end

  def check
    valid_row = '123456789' + ('A'..'Z').to_a.join
    str = self.flatten.join
    if str[-1] == '0'
      str.chop!
    else
      return false
    end

    (0...str.length).all? do |i|
      str[i] == '=' || str[i] == valid_row[i]
    end
  end

  def check_top
    valid_row = '123456789' + ('A'..'Z').to_a.join
    str = self[0].join
    (0...str.length).all? do |i|
      str[i] == '=' || str[i] == valid_row[i]
    end
  end

  def check_left
    valid_row = '123456789' + ('A'..'Z').to_a.join
    w = self[0].length
    str = map {|ary| ary[0] }.join
    (0...str.length).all? do |i|
      str[i] == '=' || str[i] == valid_row[i*w]
    end
  end

  def calc
    counter = 0
    valid_row = ('1'..'9').to_a + ('A'..'Z').to_a
    w = self[0].length
    h = self.length
    (0...h).each do |y|
      (0...w).each do |x|
        if po = find_char(valid_row.shift)
          sx = po[0]
          sy = po[1]
          counter += ((x-sx).abs + (y-sy).abs)
        end
      end
    end
    counter
  end

  def cleanup
    c = self.map {|q| q[1].calc }
    border = (c.max + c.min) / 2
    self.delete_if {|q| q[1].calc > border }
    self
  end

end