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|
#!/usr/bin/env ruby
# What can I say? I like the word reify.
vars = {}
nets = []
class Var
def initialize(name)
@name = name
@value = nil
end
attr_reader :name, :value
def reified?
!@value.nil?
end
def try_reify_numeric!
if @name =~ /\A\d+\Z/
@value = @name.to_i
end
end
def reify!(value)
@value = value
end
def reify_negative!
@value = 65536 + @value if @value < 0
end
def reset!
@value = nil
end
end
class Net
def initialize(left, op, right, out)
@left = left
@op = op
@right = right
@out = out
@reified = false
end
def reified?
@reified
end
def reifiable?
return false unless @left.nil? || @left.reified?
return false unless @right.reified?
return true
end
def reify!
case @op
when nil
@out.reify!(@right.value)
when "NOT"
@out.reify!(~@right.value)
when "AND"
@out.reify!(@left.value & @right.value)
when "OR"
@out.reify!(@left.value | @right.value)
when "LSHIFT"
@out.reify!(@left.value << @right.value)
when "RSHIFT"
@out.reify!(@left.value >> @right.value)
end
@reified = true
end
def reset!
@reified = false
end
end
File.readlines("day7.input").map(&:strip).each do |line|
input, output = line.split(" -> ")
input = input.split
vars[output] = Var.new(output) if vars[output].nil?
output = vars[output]
case input.length
when 1
vars[input[0]] = Var.new(input[0]) if vars[input[0]].nil?
nets << Net.new(nil, nil, vars[input[0]], output)
when 2
vars[input[1]] = Var.new(input[1]) if vars[input[1]].nil?
nets << Net.new(nil, input[0], vars[input[1]], output)
when 3
vars[input[0]] = Var.new(input[0]) if vars[input[0]].nil?
vars[input[2]] = Var.new(input[2]) if vars[input[2]].nil?
nets << Net.new(vars[input[0]], input[1], vars[input[2]], output)
end
end
# Part 1
vars.values.each(&:try_reify_numeric!)
until nets.all?(&:reified?)
nets.each do |net|
net.reify! if net.reifiable?
end
end
vars.values.each(&:reify_negative!)
part1 = vars["a"].value
puts "Part 1: #{part1}"
# Part 2
vars.values.each(&:reset!)
nets.each(&:reset!)
vars.values.each(&:try_reify_numeric!)
until nets.all?(&:reified?)
nets.each do |net|
vars["b"].reify!(part1)
net.reify! if net.reifiable?
end
end
vars.values.each(&:reify_negative!)
part2 = vars["a"].value
puts "Part 2: #{part2}"
|
