From cc980f097b39196bdfd763e63479fa56ab0e3df0 Mon Sep 17 00:00:00 2001
From: Eric Bailey <eric@ericb.me>
Date: Mon, 22 Jul 2024 15:25:23 -0500
Subject: [PATCH] feat(2017.08-haskell): solve Part Two

---
 VERSION                            |  2 +-
 src/AdventOfCode/Year2017/Day08.hs | 11 ++++++++++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/VERSION b/VERSION
index 02a4aff..862e7aa 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2023.6.2.24
\ No newline at end of file
+2023.6.2.25
\ No newline at end of file
diff --git a/src/AdventOfCode/Year2017/Day08.hs b/src/AdventOfCode/Year2017/Day08.hs
index 59a1ced..2a8cd4f 100644
--- a/src/AdventOfCode/Year2017/Day08.hs
+++ b/src/AdventOfCode/Year2017/Day08.hs
@@ -36,7 +36,16 @@ partOne = maximum . Map.elems . foldl' go Map.empty
         else mem
 
 partTwo :: [Instruction] -> Int
-partTwo = undefined
+partTwo = maximum . map (maximum . Map.elems) . init . foldl' go [Map.empty]
+  where
+    go (mem : history) (Ins op regAlter delta cmp regCompare comparate) =
+      mem' : mem : history
+      where
+        mem' =
+          if compareReg mem cmp regCompare comparate
+            then Map.alter (Just . flip (binOp op) delta . fromMaybe 0) regAlter mem
+            else mem
+    go [] _ = []
 
 getInput :: IO [Instruction]
 getInput = parseInput (some instruction) $(inputFilePath)