Day 10-2

day10.erl

@@ -3,7 +3,7 @@
 -export([solve/1]).
 
 solve(Input) ->
-    {part1(Input), none}.
+    {part1(Input), io:format("~s~n", [part2(Input)])}.
 
 part1(Input) ->
     History = run(Input, [{1, 1}]),
@@ -12,6 +12,24 @@ part1(Input) ->
                     Key * element(2, lists:keyfind(Key, 1, History))
             end,
     lists:sum(lists:map(Score, Interesting)).
+part2(Input) ->
+    History = run(Input, [{1, 1}]),
+    render(History, []).
+
+render([{Cycle, X}|Rest], Acc) ->
+    Prefix =
+        case Cycle rem 40 == 0 of
+            true -> "\n";
+            false -> []
+        end,
+    Symbol = 
+    if
+        X + 2 < Cycle rem 40 -> $.;
+        X > Cycle rem 40 -> $.;
+        true -> $#
+    end,
+    render(Rest, [Symbol|Prefix] ++ Acc);
+render([], Acc) -> Acc.
 
 run(<<"\n", Rest/binary>>, StateIn) ->
     run(Rest, StateIn);