minesweeper.rb

INPUT = <<-EOS
O O O O X O O O O O X
X X O X O O O O X O X
O O O X X O O O O O X
O O O O O O O O O O X
O O O O O X O O O O X
EOS
#INPUT = "BMC_TEST_INPUT_MAGIC"

MINE = "X"
MINEFREE = "O"
NEW_LINE = "\n"

def check_surrounding_fields(column_idx, row_idx)
  count = 0

  count += 1 if $matrix[row_idx-1][column_idx-1] == MINE
  count += 1 if $matrix[row_idx-1][column_idx] == MINE
  count += 1 if $matrix[row_idx-1][column_idx+1] == MINE
  count += 1 if $matrix[row_idx][column_idx-1] == MINE
  count += 1 if $matrix[row_idx][column_idx+1] == MINE
  unless row_idx + 1 >= $matrix.length
    count += 1 if $matrix[row_idx+1][column_idx-1] == MINE
    count += 1 if $matrix[row_idx+1][column_idx] == MINE
    count += 1 if $matrix[row_idx+1][column_idx+1] == MINE
  end

  return count.to_s
end

def calculate_mines_for_field(column, column_idx, row_idx)
  return column if column == MINE

  mine_count = check_surrounding_fields(column_idx, row_idx)

  return mine_count
end

if __FILE__ == $0
  $matrix = []
  row = []

  INPUT.split("").each do |field|
    if field == MINE || field == MINEFREE
      row << field
    elsif field == NEW_LINE
      $matrix << row
      row = []
    end
  end

  $matrix.each_with_index do |row, row_idx|
    row.each_with_index do |column, column_idx|
      $matrix[row_idx][column_idx] = calculate_mines_for_field(column, column_idx, row_idx)
    end
  end

  printable = ""
  $matrix.each_with_index do |row, row_idx|
    row.each_with_index do |column, column_idx|
      if column_idx + 1 == row.length
        printable << "#{column}"
        printable << "\n" unless column_idx + 1 == row.length and row_idx + 1 == $matrix.length 
      else
        printable << column + " "
      end
    end
  end

  puts printable
end