11th day

hexagons.rb

@@ -0,0 +1,21 @@
+require 'matrix'
+input = File.read("input_11.rb").strip.split(",").map(&:to_sym)
+HEX_DIRS = {
+  :n => Vector[0,1,-1], :ne => Vector[-1,1,0],
+  :se => Vector[-1,0,1], :s => Vector[0,-1,1],
+  :sw => Vector[1,-1,0], :nw => Vector[1,0,-1]  
+}
+
+def dist path
+
+  path.reduce({:vec => Vector[0,0,0], :lol => 0}) do |mem,step|
+    mem[:vec]= new = mem[:vec] + HEX_DIRS[step]
+    mem[:lol] = [new.map(&:abs).sum / 2, mem[:lol]].max
+    mem
+  end
+end
+
+out = dist input
+p out[:vec].map(&:abs).sum / 2, out[:lol]
+
+