From 2d21b30679b06949891f99d5dadffbb48ebbc2d3 Mon Sep 17 00:00:00 2001
From: Oscar Najera <hi@oscarnajera.com>
Date: Mon, 12 Dec 2022 22:26:12 +0100
Subject: same depth

---
 AoC2022/12/solver.el | 47 ++++++++++++++++++++++++++++++++---------------
 1 file changed, 32 insertions(+), 15 deletions(-)

(limited to 'AoC2022/12/solver.el')

diff --git a/AoC2022/12/solver.el b/AoC2022/12/solver.el
index 44fe525..1c68d04 100644
--- a/AoC2022/12/solver.el
+++ b/AoC2022/12/solver.el
@@ -24,8 +24,8 @@
     (delq nil
           (list
            (when (< -1 x  (1- width)) (1+ pos))      ;; right move
-           (when (<  0 x width) (1- pos))            ;; left move
            (when (< -1 y (1- height)) (+ pos width)) ;; down move
+           (when (<  0 x width) (1- pos))            ;; left move
            (when (<  0 y height) (- pos width)))))) ;; up move
 
 (should (equal (solver-directions 6 5 5) '(7 5 11 1)))
@@ -41,17 +41,27 @@
                                 row))
                       data "")))
 
-(defun solver-search (path land)
+(defun solver-next-steps (path land)
   (let* ((pos (car path))
-         (elevation (aref land pos))
-         (next-cells (solver-directions pos width height)))
+         (elevation (aref land pos)))
     (if (= 27 elevation) ;; reached destination
-        (list (reverse path))
+        (list (vconcat (reverse path)))
       (mapcan (lambda (option)
                 (when (and (not (memq option path))
                            (>= (1+ elevation) (aref land option))) ;; allowed move
-                  (solver-search (cons option path) land)))
-              next-cells))))
+                  (list (cons option path))))
+              (solver-directions pos width height)))))
+
+
+(defun solver-search (queue land)
+
+  (let* ((next (mapcan (lambda (path) (solver-next-steps path land)) queue))
+        (finish (seq-filter #'vectorp next)))
+    (cond
+     ((null next) "No solution")
+     ((null finish) (solver-search next land))
+     (finish))
+      ))
 
 (with-temp-buffer
   (insert "Sabqponm
@@ -64,12 +74,19 @@ abdefghi")
          (width (length (car data)))
          (land (solver-land data))
          (start (seq-position land 0 #'eq)))
-    (thread-first
-      (cl-sort
-       (solver-search (list start) land)
-       #'<
-       :key #'length)
-      (car)
-      (length)
-      (1-))
+    ;; (solver-search
+    ;;  land)
+    (let ((res (solver-search (list (list start)) land)))
+      (list
+       (length res)
+       (mapcar #'length res))
+      )
     ))
+
+(thread-first
+  (cl-sort
+   #'<
+   :key #'length)
+  (car)
+  (length)
+  (1-))
-- 
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