Day 2 solutions

Author: creideiki

2-1.py

@@ -0,0 +1,46 @@
+#!/usr/bin/env python
+
+import re
+import sys
+
+instructions = [insn.strip() for insn in open('2.input').readlines()]
+
+instruction_format = re.compile("(?P<inst>forward|down|up) (?P<oper>[0-9]+)")
+
+
+class Submarine:
+    def __init__(self):
+        self.horiz_pos = 0
+        self.depth = 0
+
+    def forward(self, steps):
+        self.horiz_pos += steps
+
+    def down(self, steps):
+        self.depth += steps
+
+    def up(self, steps):
+        self.depth -= steps
+        if self.depth < 0:
+            print(f"Illegal direction: up {steps}")
+            sys.exit()
+
+    def __str__(self):
+        return f"<{self.__class__.__name__}: ({self.horiz_pos}, {self.depth})>"
+
+
+sub = Submarine()
+
+for insn in instructions:
+    m = instruction_format.match(insn)
+    if m['inst'] == 'forward':
+        sub.forward(int(m['oper']))
+    elif m['inst'] == 'down':
+        sub.down(int(m['oper']))
+    elif m['inst'] == 'up':
+        sub.up(int(m['oper']))
+    else:
+        print(f"Illegal instruction: {insn}")
+        sys.exit()
+
+print(f"{sub.horiz_pos * sub.depth}")

2-1.rb

@@ -0,0 +1,55 @@
+#!/usr/bin/env ruby
+
+instructions = File.read('2.input').lines.map(&:strip)
+
+instruction_format = /(?<inst>forward|down|up) (?<oper>[[:digit:]]+)/
+
+class Submarine
+  attr_accessor :horiz_pos
+  attr_accessor :depth
+
+  def initialize
+    @horiz_pos = 0
+    @depth = 0
+  end
+
+  def forward(steps)
+    @horiz_pos += steps
+  end
+
+  def down(steps)
+    @depth += steps
+  end
+
+  def up(steps)
+    @depth -= steps
+    if @depth.negative?
+      print "Illegal instruction: up #{steps}"
+      exit
+    end
+  end
+
+  def to_s
+    "<#{self.class}: (#{@horiz_pos}, #{@depth})>"
+  end
+end
+
+sub = Submarine.new
+
+instructions.each do |insn|
+  instruction_format.match(insn) do |m|
+    case m['inst']
+    when 'forward'
+      sub.forward(m['oper'].to_i)
+    when 'down'
+      sub.down(m['oper'].to_i)
+    when 'up'
+      sub.up(m['oper'].to_i)
+    else
+      print "Illegal instruction: #{insn}\n"
+      exit
+    end
+  end
+end
+
+print "#{sub.horiz_pos * sub.depth}\n"

2-2.py

@@ -0,0 +1,48 @@
+#!/usr/bin/env python
+
+import re
+import sys
+
+instructions = [insn.strip() for insn in open('2.input').readlines()]
+
+instruction_format = re.compile("(?P<inst>forward|down|up) (?P<oper>[0-9]+)")
+
+
+class Submarine:
+    def __init__(self):
+        self.horiz_pos = 0
+        self.depth = 0
+        self.aim = 0
+
+    def forward(self, steps):
+        self.horiz_pos += steps
+        self.depth += self.aim * steps
+        if self.depth < 0:
+            print(f"Illegal direction: forward {steps}")
+            sys.exit()
+
+    def down(self, steps):
+        self.aim += steps
+
+    def up(self, steps):
+        self.aim -= steps
+
+    def __str__(self):
+        return f"<{self.__class__.__name__}: ({self.horiz_pos}, {self.depth}, {self.aim})>"
+
+
+sub = Submarine()
+
+for insn in instructions:
+    m = instruction_format.match(insn)
+    if m['inst'] == 'forward':
+        sub.forward(int(m['oper']))
+    elif m['inst'] == 'down':
+        sub.down(int(m['oper']))
+    elif m['inst'] == 'up':
+        sub.up(int(m['oper']))
+    else:
+        print(f"Illegal instruction: {insn}")
+        sys.exit()
+
+print(f"{sub.horiz_pos * sub.depth}")

2-2.rb

@@ -0,0 +1,58 @@
+#!/usr/bin/env ruby
+
+instructions = File.read('2.input').lines.map(&:strip)
+
+instruction_format = /(?<inst>forward|down|up) (?<oper>[[:digit:]]+)/
+
+class Submarine
+  attr_accessor :horiz_pos
+  attr_accessor :depth
+  attr_accessor :aim
+
+  def initialize
+    @horiz_pos = 0
+    @depth = 0
+    @aim = 0
+  end
+
+  def forward(steps)
+    @horiz_pos += steps
+    @depth += @aim * steps
+    if @depth.negative?
+      print "Illegal instruction: forward #{steps}"
+      exit
+    end
+  end
+
+  def down(steps)
+    @aim += steps
+  end
+
+  def up(steps)
+    @aim -= steps
+  end
+
+  def to_s
+    "<#{self.class}: (#{@horiz_pos}, #{@depth}, #{@aim})>"
+  end
+end
+
+sub = Submarine.new
+
+instructions.each do |insn|
+  instruction_format.match(insn) do |m|
+    case m['inst']
+    when 'forward'
+      sub.forward(m['oper'].to_i)
+    when 'down'
+      sub.down(m['oper'].to_i)
+    when 'up'
+      sub.up(m['oper'].to_i)
+    else
+      print "Illegal instruction: #{insn}\n"
+      exit
+    end
+  end
+end
+
+print "#{sub.horiz_pos * sub.depth}\n"