Lel

sudoku.rb

board_string = "003020600900305001001806400008102900700000008006708200002609500800203009005010300"

class Sudoku
  attr_accessor :board

  def initialize(string)
    @board = string
  end

  def rows
    @board.scan(/........./)
  end

  def row_permutations
    possibilities = { 1 => [], 2 => [], 3 => [], 4 => [], 5 => [], 6 => [], 7 => [], 8 => [], 9 => [] }

    rows.each_with_index do |row, index|
      row = row.chars.map(&:to_i)
      remaining_numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9] - row
      permutations = remaining_numbers.permutation.to_a

      permutations.each do |permutation|
        row_copy = row.dup

        possibilities[index+1] << row_copy.each_with_index do |num, index|
          row_copy[index] = permutation.shift if num == 0
        end
      end
    end

    p possibilities
  end

end

sudoku = Sudoku.new(board_string)

sudoku.row_permutations