15 puzzle

gistfile1.txt

# fifteen_puzzle.rb
require 'io/console'

class FifteenPuzzle
  def initialize
    start_new_game
  end

  def play
    loop do
      until solved?
        display_board
        process_input
      end
      
      display_board
      puts "Congratulations! You solved the puzzle in #{@moves} moves!"
      puts "Press 'R' to restart or 'Q' to quit"
      
      case $stdin.getch.downcase
      when 'r' then start_new_game
      when 'q' then exit
      end
    end
  end

  private

  def start_new_game
    @tiles = generate_solved_board
    @empty_position = [3, 3]
    shuffle_board
    @moves = 0
  end

  def generate_solved_board
    tiles = []
    (0..3).each do |i|
      row = []
      (0..3).each do |j|
        value = i * 4 + j + 1
        row << (value < 16 ? value : nil)
      end
      tiles << row
    end
    tiles
  end

  def shuffle_board
    directions = [:up, :down, :left, :right]
    256.times do
      valid_moves = directions.select do |dir|
        new_pos = calculate_new_position(dir)
        valid_move?(new_pos)
      end
      
      direction = valid_moves.sample
      new_position = calculate_new_position(direction)
      swap_tiles(@empty_position, new_position)
      @empty_position = new_position
    end
  end

  def process_input
    case $stdin.getch.downcase
    when 'w' then try_move(:down)
    when 's' then try_move(:up)
    when 'a' then try_move(:right)
    when 'd' then try_move(:left)
    when 'r' then start_new_game
    when 'q' then exit
    end
  end

  def try_move(direction)
    new_position = calculate_new_position(direction)
    if valid_move?(new_position)
      swap_tiles(@empty_position, new_position)
      @empty_position = new_position
      @moves += 1
    else
      puts "Invalid move!"
      sleep(0.2)
    end
  end

  def calculate_new_position(direction)
    row, col = @empty_position
    case direction
    when :up then [row + 1, col]
    when :down then [row - 1, col]
    when :left then [row, col + 1]
    when :right then [row, col - 1]
    end
  end

  def valid_move?(position)
    row, col = position
    row.between?(0, 3) && col.between?(0, 3)
  end

  def swap_tiles(pos1, pos2)
    r1, c1 = pos1
    r2, c2 = pos2
    @tiles[r1][c1], @tiles[r2][c2] = @tiles[r2][c2], @tiles[r1][c1]
  end

  def solved?
    target = (1..15).to_a + [nil]
    @tiles.flatten == target
  end

  def display_board
    system('clear') || system('cls')
    puts "\n15 PUZZLE\n"
    puts

    @tiles.each do |row|
      puts row.map { |tile| tile.nil? ? '  ' : tile.to_s.rjust(2) }.join('  ')
    end

    puts "\nMoves: #{@moves}"
    puts "Controls: WASD to move tiles, R to restart, Q to quit"
  end
end

# Start the game
FifteenPuzzle.new.play