Class: Rudoku::Board

Inherits:
Object
  • Object
show all
Defined in:
lib/rudoku.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(board) ⇒ Board

Returns a new instance of Board.



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# File 'lib/rudoku.rb', line 13

def initialize(board)
  @fields = []
  @board  = []
  @rows   = []
  @cols   = []
  @blocks = []
  @missing = []
  @stats = {
    :missing => 0,
    :solved_by_only_one_possible => 0,
    :solved_by_no_other_possible => 0,
    :solved_by_presolve => 0
  }

  # initialize rows, columns & blocks
  0.upto(8) do |i|
    @rows[i]   = Row.new(self, i)
    @cols[i]   = Col.new(self, i)
    @blocks[i] = Block.new(self, i)
  end

  i = 0
  board.each_with_index do |row, y|
    @board[y] = []

    row.each_with_index do |value, x|
      f = Field.new(self, i, x, y)
      f.value = value

      @board[y][x] = f
      @fields << f
      @missing << f if f.missing?
      i += 1
    end
  end

  # initialize the helper constructs
  @blocks.each do |block|
    block.initialize_area()
  end

  @stats[:missing] = @missing.length

  @counter = 0

  raise "Invalid field" if not valid_field?
end

Instance Attribute Details

#blocks ⇒ Object (readonly)

Returns the value of attribute blocks.



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# File 'lib/rudoku.rb', line 11

def blocks
  @blocks
end

#cols ⇒ Object (readonly)

Returns the value of attribute cols.



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# File 'lib/rudoku.rb', line 11

def cols
  @cols
end

#fields ⇒ Object (readonly)

Returns the value of attribute fields.



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# File 'lib/rudoku.rb', line 11

def fields
  @fields
end

#rows ⇒ Object (readonly)

Returns the value of attribute rows.



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# File 'lib/rudoku.rb', line 11

def rows
  @rows
end

Instance Method Details

#find_first_missing ⇒ Object 



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# File 'lib/rudoku.rb', line 191

def find_first_missing
  @fields.find{|f| f.missing?}
end

#get(x, y) ⇒ Object 



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# File 'lib/rudoku.rb', line 174

def get(x, y)
  @board[y][x]
end

#get_block(x, y) ⇒ Object 



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# File 'lib/rudoku.rb', line 186

def get_block(x, y)
  block_nr = x / 3 + y/3*3
  @blocks[block_nr] or raise "Unitialized block at #{x}/#{y} block_nr #{block_nr}"
end

#get_col(x) ⇒ Object 



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# File 'lib/rudoku.rb', line 182

def get_col(x)
  @cols[x]
end

#get_row(y) ⇒ Object 



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# File 'lib/rudoku.rb', line 178

def get_row(y)
  @rows[y]
end

#pre_solve ⇒ Object 



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# File 'lib/rudoku.rb', line 62

def pre_solve
  begin
    #puts "try"
    changed = @missing.reject! do |f|
      # create a list of all fields which are wmissing
      # in the same block, not including t the current field f
      nrs = f.available_nrs


      #puts "#{f} hat #{nrs.length} möglichkeiten: #{nrs.join(" ")}" if nrs.length == 2
      #f.mark if nrs.length ==2
      if nrs.length == 1
        @stats[:solved_by_only_one_possible] += 1
        #f.mark
        f.value = nrs.first
        true
      else
        # use the scanning method for possible other solutions
        # returns false or true

        if v = f.nr_only_possible_in_this_field
          # f.mark
          @stats[:solved_by_no_other_possible] += 1
          f.value = v
          #f.mark
          #return
          true
        else
          false
        end
      end
    end
  end while changed

  @stats[:solved_by_presolve] =
  @stats[:solved_by_no_other_possible] +
  @stats[:solved_by_only_one_possible]
end

#print_field(p = []) ⇒ Object 



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# File 'lib/rudoku.rb', line 135

def print_field(p = [])
  p = [p] unless p.kind_of?(Array)

  @board.each_with_index do |row, y|
    #row.map{|f| f.value}.map{|f| f || "_"}.each_with_index do |f, x|
    row.each_with_index do |f, x|
      t = ( f.value ? f.value.to_s : "_" ) + ( f.marked? ? "<" : " " )

      print "#{t} "

      #if p.any?{|o| x == o.x && y == o.y}
      #  print "#{f}<"
      #else
      #  print "#{f} "
      #end
      print " " if x % 3 == 2
    end
    puts
    puts if y % 3 == 2
  end

  #puts "Lösung"
  #0.upto(8) do |i|
  # print "#{@board[i][i].value} "
  #end
 #puts

  #puts
  puts "Stats"
  @stats.each do |key, value|
    puts "#{key}: #{value}"
  end

end

#solve(level = 0) ⇒ Object

returns false if there’s no possible next move, else return the valid path



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# File 'lib/rudoku.rb', line 102

def solve(level = 0)
  fm = @missing.shift

  if fm.nil?
    return true
  end

  available_nrs = fm.available_nrs

  unless available_nrs.empty?
    # try all the available nrs on this field
    available_nrs.each do |nr|

      raise "nr is nil??" if nr.nil?
      # set it
      fm.value = nr

      # and try to fill the next field
      result = solve(level + 1)

      # return true if we found a solution
      return true if result
    end
  end

  # seems like we are in a 'sackgasse', reset the value and
  # go back to the next stepp
  fm.value = nil
  @missing.unshift(fm)

  return false
end

#valid_field? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rudoku.rb', line 170

def valid_field?
  true
end