no record vector on counter

1 files changed, 9 insertions, 17 deletions

diff --git a/AoC2022/15/solver.lisp b/AoC2022/15/solver.lisp
index 9a93e1f..3471b3b 100644
--- a/AoC2022/15/solver.lisp
+++ b/AoC2022/15/solver.lisp
@@ -85,25 +85,17 @@
   (let ((bounds (bounds markers))
         (max-distance (loop for (sensor beacon) on markers by #'cddr
                             maximize (manhattan-dist sensor beacon))))
-
     (destructuring-bind ((xmin xmax) ys) bounds
       (declare (ignore ys))
-      (let* ((stride (- (+ (* 2 max-distance) xmax 1) xmin))
-             (row-min (- xmin max-distance))
-             (row (make-array stride :element-type '(unsigned-byte 1) :initial-element 0)))
-        (loop for (sensor beacon) on markers by #'cddr
-              for distance = (manhattan-dist sensor beacon)
-              when (= target-row (cdr sensor))
-                do (setf (aref row (- (car sensor) row-min)) 1)
-              when (= target-row (cdr beacon))
-                do (setf (aref row (- (car beacon) row-min)) 1)
-
-              sum (loop
-                    for x from (- xmin distance) to (+ xmax distance)
-                    when (and (<= (manhattan-dist sensor (cons x target-row)) distance)
-                              (< -1 (- x row-min) stride)
-                              (= 0 (aref row (- x row-min))))
-                      count it and do (setf (aref row (- x row-min)) 1)))))))
+      (loop with y = target-row
+            for x from (- xmin max-distance) to (+ xmax max-distance)
+            :count (loop for (sensor beacon) on markers by #'cddr
+                         :thereis (and (not (equal beacon (cons x y)))
+                                       (not (equal sensor (cons x y)))
+                                       (<= (manhattan-dist sensor (cons x y))
+                                           (manhattan-dist sensor beacon))))))))
+
+
 
 (count-cover (markers (uiop:read-file-lines "eg-in")) 10)
 (count-cover (markers (uiop:read-file-lines "input")) 2000000)