solved both parts

day12/solution1.rb

@@ -0,0 +1,47 @@
+#!/bin/env ruby
+require 'pry'
+
+def turn_ship (direction, degree, facing)
+    dirs = [:north, :east, :south, :west]
+    degree = degree / 90
+    degree = -degree if direction == 'L'
+    spin = dirs.find_index(facing) + degree
+    spin -= 4 if spin > 3
+    spin += 4 if spin < 0
+    return dirs[spin]
+end
+
+ship = {
+    :facing => :east,
+    :x_position => 0,
+    :y_position => 0 }
+
+directions = File.read('./input').split("\n")
+
+directions.each do |direction|
+    instruction = direction[0]
+    count = direction[1..-1].to_i
+
+    instruction = ship[:facing].to_s[0].upcase if instruction == 'F'
+    p [instruction, count]
+    case instruction
+    when 'N'
+        ship[:y_position] += count
+    when 'S'
+        ship[:y_position] -= count
+    when 'E'
+        ship[:x_position] += count
+    when 'W'
+        ship[:x_position] -= count
+    when 'R','L'
+        ship[:facing] = turn_ship(instruction, count, ship[:facing])
+    end
+    pp ship
+end
+
+manhattan = ship[:x_position].abs + ship[:y_position].abs
+
+p manhattan
+        
+
+#binding.pry

day12/solution2.rb

@@ -0,0 +1,70 @@
+#!/bin/env ruby
+require 'pry'
+
+def turn_ship (direction, degree, facing)
+    dirs = [:north, :east, :south, :west]
+    degree = degree / 90
+    degree = -degree if direction == 'L'
+    spin = dirs.find_index(facing) + degree
+    spin -= 4 if spin > 3
+    spin += 4 if spin < 0
+    return dirs[spin]
+end
+
+def rotate (direction, degree, waypoint)
+    degree = degree / 90
+    degree.times do
+        waypoint[:x_position], waypoint[:y_position] =
+            waypoint[:y_position], (waypoint[:x_position])
+
+        waypoint[:y_position] *= -1 if direction =='R'
+        waypoint[:x_position] *= -1 if direction == 'L'
+    end
+    return waypoint
+end
+
+
+ship = {
+    :facing => :east,
+    :x_position => 0,
+    :y_position => 0
+}
+
+waypoint = {
+    :x_position => 10,
+    :y_position => 1
+}
+
+directions = File.read('./input').split("\n")
+
+directions.each do |direction|
+    instruction = direction[0]
+    count = direction[1..-1].to_i
+
+    p [instruction, count]
+    case instruction
+    when 'F'
+        count.times do
+            ship[:x_position] += waypoint[:x_position]
+            ship[:y_position] += waypoint[:y_position]
+        end
+    when 'N'
+        waypoint[:y_position] += count
+    when 'S'
+        waypoint[:y_position] -= count
+    when 'E'
+        waypoint[:x_position] += count
+    when 'W'
+        waypoint[:x_position] -= count
+    when 'R','L'
+        waypoint = rotate(instruction, count, waypoint)
+    end
+    pp ship
+end
+
+manhattan = ship[:x_position].abs + ship[:y_position].abs
+
+p manhattan
+        
+
+#binding.pry