simulator.rb

class Simulator

	def initialize(seating_arrangement)
		@curState = seating_arrangement
		@nextState = @curState
	end

	def verdict
		
		opinion = { :hard => 0,	:soft => 0, :none => 0 }

		@curState.each do |col|
			col.each do |row|
				opinion[row] += 1
			end
		end

		return :hard if opinion[:hard] > opinion[:soft]
		return :soft if opinion[:soft] > opinion[:hard]
		return :push
	end

	def state
		return @curState
	end

	def next
		@nextState = Marshal.load(Marshal.dump(@curState))
		(0..(@curState.length - 1)).each do |i|
			(0..(@curState[i].length - 1)).each do |j|
				opinion(i,j)
			end
		end
		@curState = @nextState.clone
	end

	def opinion(i, j)
		neighbours = {:hard => 0, :soft => 0, :none => 0}
		(-1..1).each do |iN|
			(-1..1).each do |jN|
				iPos = i + iN
				jPos = j + jN

				next if jN == 0 and iN == 0
				
				next if not iPos.between?(0, @curState.length - 1)

				next if not jPos.between?(0, @curState[iPos].length - 1)

				neighbours[@curState[iPos][jPos]] += 1
			end
		end

		# fewer than 2 opinionated neighbours, lose opinion
		if neighbours[:hard] + neighbours[:soft] < 2 then
			@nextState[i][j] = :none
			return
		end

		# more than 3 opinionated, lose opinion
		if neighbours[:hard] + neighbours[:soft] > 3 then
			@nextState[i][j] = :none
			return
		end

		# 3 with >= 2 hard, become hard if no opinion
		if neighbours[:hard] + neighbours[:soft] == 3 and neighbours[:hard] >= 2 and @curState[i][j] == :none then
			@nextState[i][j] = :hard
			return
		end

		# 3 with >= 2 soft, become soft if no opinion
		if neighbours[:hard] + neighbours[:soft] == 3 and neighbours[:soft] >= 2 and @curState[i][j] == :none then
			@nextState[i][j] = :soft
			return
		end

	end

end