[AoC2022] Elisp Day 14 two parts

1 files changed, 42 insertions, 26 deletions

diff --git a/AoC2022/14/solver.el b/AoC2022/14/solver.el
index 0ad36fb..c051f98 100644
--- a/AoC2022/14/solver.el
+++ b/AoC2022/14/solver.el
@@ -31,13 +31,7 @@
         (setq ymin (min ymin (string-to-number (match-string 2)))))
       (list xmax xmin ymax ymin))))
 
-(cl-defstruct (grid (:constructor solver-grid-create
-                                  (bounds
-                                   &aux
-                                   (x-len (1+ (- (car bounds) (cadr bounds))))
-                                   (y-len (1+ (elt bounds 2)))
-                                   (stride (* 8 (1+ (/ x-len 8))))
-                                   (grid (make-vector (* stride y-len) 0))))
+(cl-defstruct (grid (:constructor solver-grid--create)
                     (:copier nil))
   "Represents a snapshot of game of life."
   bounds
@@ -46,9 +40,30 @@
   stride
   grid)
 
+
+(defun solver-abyss-grid (bounds)
+  (let* ((x-len (1+ (- (car bounds) (cadr bounds))))
+         (y-len (1+ (elt bounds 2)))
+         (stride (* 8 (if (= 0 (mod x-len 8))
+                          (/ x-len 8)
+                        (1+ (/ x-len 8)))))
+         (grid (make-vector (* stride y-len) 0)))
+    (solver-grid--create :bounds bounds :x-len x-len :y-len y-len :stride stride :grid grid)))
+
+(defun solver-finite-grid (bounds)
+  (let* ((y-len (+ 3 (elt bounds 2)))
+         (x-len (* 2 y-len))
+         (stride (* 8 (if (= 0 (mod x-len 8))
+                          (/ x-len 8)
+                        (1+ (/ x-len 8)))))
+         (grid (make-vector (* stride y-len) 0)))
+    (setcar bounds (+ 500 y-len))
+    (setf (elt bounds 1) (- 500 y-len))
+    (solver-grid--create :bounds bounds :x-len x-len :y-len y-len :stride stride :grid grid)))
+
 (defun solver-point (x y grid)
   (let ((x (- x (cadr (grid-bounds grid)))))
-    (when (and (< -1 (grid-x-len grid))
+    (when (and (< -1 x (grid-x-len grid))
                (< -1 y (grid-y-len grid)))
       (+ x (* y (grid-stride grid))))))
 
@@ -66,7 +81,7 @@
         (setq startx fx
               starty fy)))))
 
-(defun solver-walls (str-or-buffer grid)
+(defun solver-walls (str-or-buffer grid &optional finite-grid)
   (with-temp-buffer
     (if (stringp str-or-buffer)
         (insert str-or-buffer)
@@ -75,12 +90,15 @@
     (while (not (eobp))
       (solver--wall-line grid)
       (forward-line)))
+  (when finite-grid
+    (cl-loop with yrow = (* (grid-stride grid) (1- (grid-y-len grid)))
+             for x from 0 below (grid-x-len grid)
+             do (aset (grid-grid grid) (+ x yrow) 1)))
   grid)
 
 (defun solver-draw-wall (grid)
   (let ((array (copy-sequence (grid-grid grid)))
-        (stride (grid-stride grid))
-        (y-len (grid-y-len grid)))
+        (stride (grid-stride grid)))
     (create-image array
                   'xbm t
                   :scale 20
@@ -103,13 +121,6 @@
                    (2 "o")))))
      (grid-grid grid))))
 
-
-(solver-walls "498,4 -> 498,6 -> 496,6
-503,4 -> 502,4 -> 502,9 -> 494,9"
-              (solver-grid-create '(503 494 9 4)))
-
-(solver-point 496 3 (solver-grid-create '(503 494 9 4)))
-
 (defun solver-simulate (grid)
   (let ((x 500) (y 0) (drops 0))
     (while
@@ -125,16 +136,21 @@
             (cl-incf x)) ;; check right
            (t (aset (grid-grid grid) (solver-point x y grid) 2)
               (cl-incf drops)
-              (setq x 500 y 0)))))
+              (unless (= y 0)
+                (setq x 500 y 0))))))
     drops))
 
-(defun solver-part1 (instructions)
+(defun solver (instructions grid-type)
   (let* ((bounds (solver-bounds instructions))
-        (grid (solver-grid-create bounds)))
-    (solver-walls instructions grid)
+        (grid (funcall grid-type bounds)))
+    (solver-walls instructions grid (eq #'solver-finite-grid grid-type))
     (solver-simulate grid)))
 
-(ert-deftest test-part1 ()
-  (should (= 24 (solver-part1 "498,4 -> 498,6 -> 496,6
-503,4 -> 502,4 -> 502,9 -> 494,9")))
-  (should (= 665 (solver-part1 (find-file-noselect "input")))))
+(ert-deftest test ()
+  (should (= 24 (solver "498,4 -> 498,6 -> 496,6
+503,4 -> 502,4 -> 502,9 -> 494,9" #'solver-abyss-grid)))
+  (should (= 665 (solver (find-file-noselect "input") #'solver-abyss-grid)))
+  (should (= 93 (solver "498,4 -> 498,6 -> 496,6
+503,4 -> 502,4 -> 502,9 -> 494,9" #'solver-finite-grid)))
+  (should (= 25434 (solver (find-file-noselect "input") #'solver-finite-grid))))
+