From 1843eac277feb37d9fd1ae1a60157f041333ad8c Mon Sep 17 00:00:00 2001
From: Alex Karle <alex@alexkarle.com>
Date: Sat, 3 Dec 2022 01:06:00 -0500
Subject: [PATCH] day3: Add part 2

---
 2022/03/sol.scm | 36 +++++++++++++++++++++++++++++++-----
 1 file changed, 31 insertions(+), 5 deletions(-)

diff --git a/2022/03/sol.scm b/2022/03/sol.scm
index f14ee74..685cc69 100755
--- a/2022/03/sol.scm
+++ b/2022/03/sol.scm
@@ -32,11 +32,37 @@
                (if (member x r) (prio x) 0))
              l))))
 
+; this could be optimized by sorting first
+(define (uniq lst)
+  (if (null? lst)
+      lst
+      (if (member (car lst) (cdr lst))
+          (uniq (cdr lst))
+          (cons (car lst) (uniq (cdr lst))))))
+
+(define (score-group a b c)
+  (apply +
+         (map (lambda (x)
+                (if (and (member x b) (member x c))
+                    (prio x)
+                    0))
+               a)))
+
+(define (part-2 packs)
+  (let loop ((i 0) (score 0) (pks (map uniq packs)))
+    (if (null? pks)
+        score
+        (if (= (modulo i 3) 0)
+            (loop (add1 i)
+                  (+ score (score-group (car pks) (cadr pks) (caddr pks)))
+                  (cdr pks))
+            (loop (add1 i) score (cdr pks))))))
+
+
 (define (main args)
   (let* ((lines (read-lines))
          (packs (map string->list lines))
-         (scores (map score-pack packs)))
-    (print (car packs))
-    (print (bisect (car packs)))
-    (print (score-pack (car packs)))
-    (print (apply + scores))))
+         (scores-1 (map score-pack packs))
+         (score-2 (part-2 packs)))
+    (print (apply + scores-1))
+    (print score-2)))
--
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