Class: Sudokude::Sudoku

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

Instance Method Summary collapse

Constructor Details

#initialize(sudoku) ⇒ Sudoku

Returns a new instance of Sudoku.



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# File 'lib/sudokude.rb', line 3

def initialize(sudoku)
  raise "This is not the proper size" if sudoku.map {|e| e.size } != [9,9,9,9,9,9,9,9,9]
  @sudoku = {}
  j = 0

  # This code creates a hash table with key indexes for each value.
  # The key is made up of three digits and shows the exact location
  # of the number.
  sudoku.each do |row|
    9.times do |i|
      if i <= 2 && j <= 2
        b = 0
      elsif i <= 5 && j <= 2
        b = 1
      elsif i > 5 && j <= 2
        b = 2
      elsif i <= 2 && j <= 5
        b = 3
      elsif i <= 5 && j <= 5
        b = 4
      elsif i > 5 && j <= 5
        b = 5
      elsif i <= 2 && j > 5
        b = 6
      elsif i <= 5 && j > 5
        b = 7
      else
        b = 8
      end
      @sudoku[i.to_s + j.to_s + b.to_s] = row[i]
    end
    j += 1
  end
end

Instance Method Details



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# File 'lib/sudokude.rb', line 38

def print
  self.each do |row| 
    row.map! do |e| 
      if e.nil?
        "n"
      else
        e
      end
    end
    puts row.join(" ")
  end
end

#solve! ⇒ Object 



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# File 'lib/sudokude.rb', line 51

def solve!
  unsolved = {}
  @keysizes = []
  @sudoku.each do |key, value|
    if value.nil?
      unsolved[key] = [1,2,3,4,5,6,7,8,9]
    end
  end

  until solved

    # Simple elimination method
    unsolved.each do |key, value|
      value.reject! do |number| 
        (@sudoku.row(key[1].to_i) + @sudoku.column(key[0].to_i) + @sudoku.box(key[2].to_i)).include?(number)
      end
      @sudoku[key] = value[0] if value.size == 1
      unsolved.delete_if { |key, value| value.empty? }
    end

    
    # Naked multiples method
    unsolved.each do |key, value|
      if unsolved.row(key[1].to_i).has_naked_multiple?(value)
        unsolved.each do |nkey, nvalue|
          nvalue.reject! { |n| value.include?(n) } if (!(nvalue-value).empty? && key[1] == nkey[1])
        end
      end
      if unsolved.column(key[0].to_i).has_naked_multiple?(value)
        unsolved.each do |nkey, nvalue|
          nvalue.reject! { |n| value.include?(n) } if (!(nvalue-value).empty? && key[0] == nkey[0])
        end
      end
      if unsolved.box(key[2].to_i).has_naked_multiple?(value)
        unsolved.each do |nkey, nvalue|
          nvalue.reject! { |n| value.include?(n) } if (!(nvalue-value).empty? && key[2] == nkey[2])
        end
      end

      @sudoku[key] = value[0] if value.size == 1
      unsolved.delete_if { |key, value| value.empty? }
    end

    if unsolvable
      puts "Impossible to solve. Best solution (n if no solution):"
      break
    end  
  end

  return @sudoku.values.each_slice(9).to_a

end