From 1c4d96edf445e9046393197623fdb76121433818 Mon Sep 17 00:00:00 2001
From: Shanti Chellaram <shanti@shanti.im>
Date: Mon, 12 Dec 2022 01:19:09 +0900
Subject: [PATCH] Day 11-2

---
 day11.erl | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/day11.erl b/day11.erl
index 83dd12e..c1a8f2d 100644
--- a/day11.erl
+++ b/day11.erl
@@ -4,7 +4,18 @@
 
 solve(Input) ->
     Monkeys = parse_monkeys(Input),
-    {score(run(20, Monkeys)), none}.
+    Monkeys1 = worry_management(Monkeys, 1),
+    Monkeys2 = worry_management(Monkeys, 2),
+    {score(run(20, Monkeys1)), score(run(10000, Monkeys2))}.
+
+worry_management(Monkeys, Part) ->
+    Product = maps:fold(fun(_, #{test_divisor := TestDivisor}, Acc) -> Acc * TestDivisor end, 1, Monkeys),
+    maps:map(fun (_, #{operation := Operation} = Monkey) ->
+                     Monkey#{operation :=
+                             case Part of
+                                 1 -> fun (Level) -> Operation(Level) div 3 end;
+                                 2 -> fun (Level) -> Operation(Level) rem Product end
+                             end} end, Monkeys).
 
 score(Monkeys0) ->
     Monkeys1 = maps:values(Monkeys0),
@@ -38,7 +49,7 @@ increment_interacts(Monkey) ->
 
 throw_item(Monkeys, From, To) ->
     #{From := #{operation := Op, queue:= [Item|FromQueue]} = FromMonkey, To := #{queue := ToQueue} = ToMonkey} = Monkeys,
-    Monkeys#{From := increment_interacts(FromMonkey#{queue:=FromQueue}), To := ToMonkey#{queue := ToQueue ++ [Op(Item) div 3]}}.
+    Monkeys#{From := increment_interacts(FromMonkey#{queue:=FromQueue}), To := ToMonkey#{queue := ToQueue ++ [Op(Item)]}}.
 
 parse_monkeys(Input) -> parse_monkeys(Input, #{}).
 
@@ -57,8 +68,8 @@ parse_monkeys(Input, Storage) ->
     True = TrueDigit - $0,
     <<"    If false: throw to monkey ", FalseDigit, $\n, Rest9/binary>> = Rest8,
     False = FalseDigit - $0,
-    Test = fun (Var) -> case (Var div 3) rem TestDivisor of 0 -> True; _ -> False end end,
-    parse_monkeys(Rest9, Storage#{MonkeyNumber => #{queue => Items, operation => Operation, test => Test}}).
+    Test = fun (Var) -> case Var rem TestDivisor of 0 -> True; _ -> False end end,
+    parse_monkeys(Rest9, Storage#{MonkeyNumber => #{queue => Items, operation => Operation, test_divisor => TestDivisor, test => Test}}).
 
 parse_operation(<<$\n, Rest/binary>>, [Rhs, Op, Lhs]) -> {fun(Old) -> Op(Rhs(Old), Lhs(Old)) end, Rest};
 parse_operation(<<$\s, Rest/binary>>, Acc) -> parse_operation(Rest, Acc);