From 8aefac562bbcadcabbada6bab08d3a7a0a612424 Mon Sep 17 00:00:00 2001
From: Oscar Najera <hi@oscarnajera.com>
Date: Sun, 3 Dec 2023 23:01:07 +0100
Subject: day02 refactor with struct

---
 AoC2023/day02/solver.lisp | 60 ++++++++++++++++++++++-------------------------
 1 file changed, 28 insertions(+), 32 deletions(-)

(limited to 'AoC2023/day02')

diff --git a/AoC2023/day02/solver.lisp b/AoC2023/day02/solver.lisp
index 60aa3cf..c0c0d70 100644
--- a/AoC2023/day02/solver.lisp
+++ b/AoC2023/day02/solver.lisp
@@ -1,10 +1,14 @@
 (ql:quickload '(uiop fiveam cl-ppcre))
+
 (defparameter eg-input "Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
 Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue
 Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red
 Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red
 Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green")
 
+(defstruct bag
+  (red 0) (blue 0) (green 0))
+
 (defun parse-set (info)
   (let (list)
     (cl-ppcre:do-register-groups ((#'parse-integer count) (#'read-from-string color))
@@ -12,28 +16,36 @@ Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green")
       (push (list color count) list))
     list))
 
-(defun in-limits (max-red max-green max-blue)
-  (lambda (value)
-    (destructuring-bind (color count) value
-      (<= count
-          (ecase color
-            (red max-red)
-            (green max-green)
-            (blue max-blue))))))
+(defun in-limits (bag)
+  (lambda (sample)
+    (every (lambda (value)
+             (destructuring-bind (color count) value
+               (<= count (slot-value bag color))))
+           (parse-set sample))))
 
 (defun parse-game (game-bounds)
   (lambda (line)
     (destructuring-bind (game . sets)
         (uiop:split-string line :separator '(#\; #\:))
-      (if (every
-           (lambda (s)
-             (every game-bounds (parse-set s)))
-           sets)
+      (if (every game-bounds sets)
           (parse-integer (cl-ppcre:scan-to-strings "\\d+" game))
           0))))
 
+(defun bag-power (bag)
+  (with-slots (red blue green) bag
+    (* red blue green)))
+
+(defun max-set (top set)
+  (loop for (color count) in set do
+    (setf (slot-value top color)
+          (max (slot-value top color) count)))
+  top)
+
 (defun game-powers (line)
-  (apply #'* (mapcar #'cadr (parse-set (cdr (uiop:split-string line :separator '(#\; #\:)))))))
+  (bag-power
+   (reduce #'max-set (cdr (uiop:split-string line :separator '(#\; #\:)))
+           :key #'parse-set
+           :initial-value (make-bag))))
 
 (defun solve1 (lines bounds)
   (reduce
@@ -41,36 +53,20 @@ Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green")
    lines
    :key (parse-game bounds)))
 
-
-(defun max-set (top set)
-  (loop for (color count) in set do
-    (let ((var (ecase color
-                 (red 0)
-                 (green 1)
-                 (blue 2))))
-      (setf (elt top var) (max (elt top var) count))))
-  top)
-
 (defun solve2 (lines)
-  (apply #'+
-         (mapcar (lambda (line)
-                   (apply #'*
-                          (reduce #'max-set (cdr (uiop:split-string line :separator '(#\; #\:)))
-                                  :key #'parse-set
-                                  :initial-value (make-list 3 :initial-element 0))))
-                 lines)))
+  (reduce #'+ lines :key #'game-powers))
 
 (fiveam:test solutions
   (fiveam:is
    (= 8
       (solve1
        (uiop:split-string eg-input :separator '(#\Newline))
-       (in-limits 12 13 14))))
+       (in-limits (make-bag :red 12 :green 13 :blue 14 )))))
   (fiveam:is
    (= 2369
       (solve1
        (uiop:read-file-lines "input")
-       (in-limits 12 13 14))))
+       (in-limits (make-bag :red 12 :green 13 :blue 14 )))))
   (fiveam:is
    (= 2286
       (solve2 (uiop:split-string eg-input :separator '(#\Newline)))))
-- 
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