Winslett

#!/usr/bin/env ruby

# construct the array of possibilities
def construct_board(board)
  unknown_count = 0

  board.each_with_index do |row, row_index|
    row.each_with_index do |cell_value, column_index|
      if cell_value.nil?
        board[row_index][column_index] = (1..9).to_a