gameoflife.rb

infile = ARGV[0]
@gridsize = ARGV[1].to_i


@world = Array.new(@gridsize+2){|i| Array.new(@gridsize+2){"."}}

File.open(infile, "r") do |f|
  (1..@gridsize).each do |i|
    row = f.gets
    rowarr = row.split(" ")
    (0..@gridsize-1).each do |j|
      @world[i][j+1] = rowarr[j]
    end
  end
end

def num_neighbours(i, j)
  count = 0
  (i-1..i+1).each do |a|
    (j-1..j+1).each do |b|
      unless (i == a) && (j == b)
        count += 1 if @world[a][b] == "X"
      end
    end
  end
  count
end

def render()
  line = ""
  (1..@world.length-2).each do |i|
    line = ""
    (1..@world[i].length-2).each do |j|
      line += "#{@world[i][j]} "
    end
    puts line
  end
end




def tick()
  new_world =  Array.new(@gridsize+2){|i| Array.new(@gridsize+2){"."}}

  (1..@gridsize).each do |i|
    (1..@gridsize).each do |j|
      tmp = num_neighbours(i,j)
      #puts "DEBUG: tmp = #{tmp}"
      if(tmp < 2)
        new_world[i][j] = "."
      elsif(tmp > 3)
        new_world[i][j] = "."
      elsif(tmp == 3)
        new_world[i][j] = "X"
      else #if tmp == 2
        if @world[i][j] == "X"
          new_world[i][j] = "X"
        else
          new_world[i][j] = "."
        end
      end
    end
  end
  @world = new_world.clone

  render
end


render
10.times do
  puts "-------------------"
  tick
end