The Game of Life, also known simply as Life, is a cellular automaton devised by the British mathematician John Horton Conway. The "game" is a zero-player game, meaning that its evolution is determined by its initial state, requiring no further input. One interacts with the Game of Life by creating an initial configuration and observing how it ev…

game_of_life.rb

class GameOfLife
  def initialize(name, size, generations, initial_life=nil)
    @size = size
    @board = new_board
    populate_board(initial_life)
    print_board(name, 0)
    
    reason = generations.times do |gen|
      prev_board = @board 
      @board = evolve
      print_board(name, gen+1)
      break :static   if prev_board == @board  
    end
    if reason == :static   then puts "no movement"
    else                        puts "specified lifetime ended"
    end
  end

  def new_board
    Array.new(@size) {Array.new(@size, 0)}
  end

  def populate_board(points=nil)
    if points.nil? 
      @size.times { |x| @size.times { |y| @board[rand(@size)][rand(@size)] = 1 } } 
    else
       points.each do |x,y|
         @board[y][x] = 1
       end
    end
  end
  
  def evolve
     new = new_board
    @size.times { |x| @size.times { |y| new[x][y] = fate(x, y) }}
    new
  end

  def fate(i, j)
    i1 = [0, i-1].max; i2 = [i+1, @size-1].min
    j1 = [0, j-1].max; j2 = [j+1, @size-1].min
    sum = 0 
    for x in i1..i2
      for y in j1..j2
        sum += @board[x][y] if !(x == i and y == j)
      end 
    end
    (sum == 3 or (sum == 2 and @board[i][j] == 1)) ? 1 : 0
  end


  def print_board(name, generation)
    puts "#{name}: generation #{generation}"
    @board.each {|row| row.each {|val| print "#{val == 1 ? '#' : '.'} "}; puts}
  end  
end
GameOfLife.new "blinker", 3, 2, [[1,0],[1,1],[1,2]]
GameOfLife.new "glider", 4, 4, [[1,0],[2,1],[0,2],[1,2],[2,2]] 
GameOfLife.new "random", 5, 5