Make space for two-digit days

2019/day05/intcode.rb

@@ -0,0 +1,203 @@
+# frozen_string_literal: true
+
+require 'forwardable'
+
+module Intcode
+  def self.read(filename)
+    parse File.read(filename)
+  end
+
+  def self.parse(input)
+    parsed = input
+             .gsub(/^#.*$/, '')
+             .gsub('\s', '')
+             .split(',')
+             .map(&:to_i)
+    Program.new parsed
+  end
+
+  class Program
+    def initialize(mem)
+      @input = nil
+      @initial_state = mem
+    end
+
+    def run(&user_input)
+      mem = Memory.new(@initial_state.clone)
+      Executor.new(mem).run(&user_input)
+    end
+  end
+
+  class Memory
+    extend Forwardable
+
+    def_delegator :@cells, :[]
+    def_delegator :@cells, :[]=
+
+    def initialize(cells)
+      @cells = cells
+    end
+
+    def to_s
+      batch_size = 10
+      output = String.new
+      @cells.each_slice(batch_size).each_with_index do |batch, idx|
+        prefix = idx * batch_size
+        output << "#{prefix}: #{batch.join(' ')}\n"
+      end
+      output
+    end
+  end
+
+  class Executor
+    def initialize(mem)
+      @mem = mem
+      @ip = 0
+    end
+
+    def run(&user_input)
+      loop do
+        return if tick(&user_input) == :done_executing
+      end
+    end
+
+    def tick(&user_input)
+      case operation(@mem[@ip])
+      when 1
+        add!
+      when 2
+        mul!
+      when 3
+        input!(&user_input)
+      when 4
+        output!
+      when 5
+        branch_if_not_zero!
+      when 6
+        branch_if_zero!
+      when 7
+        less_than!
+      when 8
+        equal!
+      when 99
+        :done_executing
+      else
+        raise StandardError, "unexpected opcode: #{opcode}"
+      end
+    end
+
+    private
+
+    def add!
+      mode = modes(@mem[@ip])
+      a = read(@ip + 1, mode[0])
+      b = read(@ip + 2, mode[1])
+      r = @mem[@ip + 3]
+      raise StandardError, "unexpected mode: #{mode[2]}" if mode[2] != 0
+
+      @mem[r] = a + b
+      @ip += 4
+    end
+
+    def mul!
+      mode = modes(@mem[@ip])
+      a = read(@ip + 1, mode[0])
+      b = read(@ip + 2, mode[1])
+      r = @mem[@ip + 3]
+      raise StandardError, "unexpected mode: #{mode[2]}" if mode[2] != 0
+
+      @mem[r] = a * b
+      @ip += 4
+    end
+
+    def input!(&user_input)
+      mode = modes(@mem[@ip])
+      r = @mem[@ip + 1]
+      raise StandardError, "unexpected mode: #{mode[0]}" if mode[0] != 0
+
+      @mem[r] = input(&user_input)
+      @ip += 2
+    end
+
+    def output!
+      mode = modes(@mem[@ip])
+      output = read(@ip + 1, mode[0])
+      puts "output: #{output}"
+      @ip += 2
+    end
+
+    def branch_if_not_zero!
+      mode = modes(@mem[@ip])
+      a = read(@ip + 1, mode[0])
+      b = read(@ip + 2, mode[1])
+      @ip = a.zero? ? @ip + 3 : b
+    end
+
+    def branch_if_zero!
+      mode = modes(@mem[@ip])
+      a = read(@ip + 1, mode[0])
+      b = read(@ip + 2, mode[1])
+      @ip = a.zero? ? b : @ip + 3
+    end
+
+    def less_than!
+      mode = modes(@mem[@ip])
+      a = read(@ip + 1, mode[0])
+      b = read(@ip + 2, mode[1])
+      r = @mem[@ip + 3]
+      raise StandardError, "unexpected mode: #{mode[2]}" if mode[2] != 0
+
+      @mem[r] = a < b ? 1 : 0
+      @ip += 4
+    end
+
+    def equal!
+      mode = modes(@mem[@ip])
+      a = read(@ip + 1, mode[0])
+      b = read(@ip + 2, mode[1])
+      r = @mem[@ip + 3]
+      raise StandardError, "unexpected mode: #{mode[2]}" if mode[2] != 0
+
+      @mem[r] = a == b ? 1 : 0
+      @ip += 4
+    end
+
+    def input
+      print 'input> '
+      if block_given?
+        inp = yield
+        puts inp
+        return inp
+      end
+
+      gets.to_i
+    end
+
+    def operation(cell)
+      (cell % 100)
+    end
+
+    def modes(cell)
+      m = Hash.new(0)
+      (cell / 100).truncate.digits.each_with_index do |d, i|
+        m[i] = d
+      end
+      m
+    end
+
+    def param(val, mode)
+      case mode
+      when 0
+        @mem[val]
+      when 1
+        val
+      else
+        raise StandardError, "unexpected mode: #{mode}"
+      end
+    end
+
+    def read(addr, mode)
+      param(@mem[addr], mode)
+    end
+  end
+end

2019/day05/part1.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+require_relative 'intcode'
+
+input = File.join(__dir__, 'input')
+program = Intcode.read(input)
+program.run

2019/day05/part2.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+require_relative 'intcode'
+
+input = File.join(__dir__, 'input')
+program = Intcode.read(input)
+program.run { 5 }