From d3aa836a8fb8be599e28c54fd029cb90f1b62631 Mon Sep 17 00:00:00 2001
From: wi11-holdsworth <83637728+wi11-holdsworth@users.noreply.github.com>
Date: Wed, 24 Sep 2025 14:54:13 +1000
Subject: [PATCH] feat: implement feedback

---
 Proj2.hs | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/Proj2.hs b/Proj2.hs
index a9d30b6..6a23ce6 100644
--- a/Proj2.hs
+++ b/Proj2.hs
@@ -11,6 +11,9 @@ module Proj2
 where
 
 type GameState = ()
+import Data.List
+import Data.Set qualified as S
+
 
 data Note = A | B | C | D | E | F | G
   deriving (Eq, Show, Ord)
@@ -58,7 +61,22 @@ toPitch [note, octave] = Pitch <$> charToNote note <*> charToOctave octave
 toPitch _ = Nothing
 
 feedback :: [Pitch] -> [Pitch] -> (Int, Int, Int)
-feedback _ _ = (0, 0, 0)
+feedback target guess = (length correctPitches, correctNotes, correctOctaves)
+  where
+    targetSet = S.fromList target
+    guessSet = S.fromList guess
+
+    correctPitches = S.intersection targetSet guessSet
+    newTarget = S.difference targetSet correctPitches
+    newGuess = S.difference guessSet correctPitches
+
+    targetNoteSet = S.map note newTarget
+    guessNoteSet = S.map note newGuess
+    targetOctaveSet = S.map octave newTarget
+    guessOctaveSet = S.map octave newGuess
+
+    correctNotes = length $ S.intersection targetNoteSet guessNoteSet
+    correctOctaves = length $ S.intersection targetOctaveSet guessOctaveSet
 
 -- implement me
 initialGuess :: ([Pitch], GameState)