From 5e2eaabb759ee78c981925e83bbddfb574880f89 Mon Sep 17 00:00:00 2001
From: Oscar Najera <hi@oscarnajera.com>
Date: Tue, 13 Dec 2022 19:32:03 +0100
Subject: CL cleanup and part2

---
 AoC2022/08/solver.lisp | 91 ++++++++++++++++++++++++++++++++------------------
 1 file changed, 59 insertions(+), 32 deletions(-)

(limited to 'AoC2022')

diff --git a/AoC2022/08/solver.lisp b/AoC2022/08/solver.lisp
index 9031e19..3cab1c0 100644
--- a/AoC2022/08/solver.lisp
+++ b/AoC2022/08/solver.lisp
@@ -11,35 +11,62 @@
     (lambda (y x)
       (funcall xminor x y))))
 
-(let* ((data (uiop:read-file-lines "input"))
-       (width (length (car data)))
-       (height (length data))
-       (forest-arr
-         (apply #'vector
-                (mapcan (lambda (row)
-                          (map 'list (lambda (x) (- (char-code x) 48)) row)) data)))
-       (visibility-mask (make-array (* width height) :initial-element nil))
-       (location-x (coord-x-minor width height))
-       (location-y (coord-y-minor width height))
-       )
-  (flet ((toggle-visibility (major minor location reverse)
-           (dotimes (m major)
-             (let ((range (loop for i below minor collect i)))
-               (loop
-                 for n in (if reverse (nreverse range) range)
-                 for maxh = -1 then (max maxh tree-height)
-                 for tree-height = (aref forest-arr (funcall location n m))
-                 when (> tree-height maxh)
-                   do (setf (aref visibility-mask (funcall location n m)) t))))))
-    (toggle-visibility height width location-x nil)
-    (toggle-visibility height width location-x t)
-    (toggle-visibility width height location-y nil)
-    (toggle-visibility width height location-y t)
-    )
-
-
-
-
-  (loop for v across visibility-mask counting v)
-  ;; visibility-mask
-  )
+(defun flatten-data (data)
+  (apply #'vector
+         (mapcan (lambda (row)
+                   (map 'list (lambda (x) (- (char-code x) 48)) row)) data)))
+
+(defun forest (data)
+  (let ((width (length (car data)))
+        (height (length data)))
+    (values (flatten-data data) width height)))
+
+(defun solver-p1 (filename)
+  (multiple-value-bind (forest-arr width height) (forest (uiop:read-file-lines filename))
+    (let ((visibility-mask (make-array (* width height) :initial-element nil))
+          (location-x (coord-x-minor width height))
+          (location-y (coord-y-minor width height)))
+      (flet ((toggle-visibility (major minor location reverse)
+               (let ((range (if reverse
+                                (loop for i downfrom (1- minor) to 0 collect i)
+                                (loop for i below minor collect i))))
+                 (dotimes (m major)
+                   (loop
+                     for n in range
+                     for maxh = -1 then (max maxh tree-height)
+                     for tree-height = (aref forest-arr (funcall location n m))
+                     when (> tree-height maxh)
+                       do (setf (aref visibility-mask (funcall location n m)) t))))))
+        (toggle-visibility height width location-x nil)
+        (toggle-visibility height width location-x t)
+        (toggle-visibility width height location-y nil)
+        (toggle-visibility width height location-y t))
+      (loop for v across visibility-mask counting v))))
+
+(defun solver-p2 (filename)
+  (multiple-value-bind (forest-arr width height) (forest (uiop:read-file-lines filename))
+    (let ((score (make-array (* width height)))
+          (location-x (coord-x-minor width height)))
+
+      (flet ((score-direction (base dir)
+               (loop for l in dir
+                     for tree-height = (aref forest-arr l)
+                     count l until (>= tree-height base))))
+        (dotimes (y height)
+          (dotimes (x width)
+            (let ((base (aref forest-arr (funcall location-x x y))))
+              (setf (aref score (funcall location-x x y))
+                    (*
+                     (score-direction base (loop for l from (1+ x) below width  collect (funcall location-x l y))) ;; to right
+                     (score-direction base (loop for l from (1+ y) below height collect (funcall location-x x l))) ;; to bottom
+                     (score-direction base (loop for l downfrom (1- x) to 0 collect (funcall location-x l y))) ;; to left
+                     (score-direction base (loop for l downfrom (1- y) to 0 collect (funcall location-x x l)))))))) ;; to top
+        (loop for v across score maximize v)))))
+
+(fiveam:test solutions
+  (fiveam:is (= 21 (solver-p1 "eg-in")))
+  (fiveam:is (= 1672 (solver-p1 "input")))
+  (fiveam:is (= 8 (solver-p2 "eg-in")))
+  (fiveam:is (= 327180 (solver-p2 "input"))))
+
+(fiveam:run-all-tests)
-- 
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