[p10] failed attempts for part 2

lib/lib-advent.org

@@ -81,10 +81,14 @@
  Add this function as an ~:around~ advice to any function to have its
  results cached in ~cache~. The symbol ~cache~ should be already bound
   #+begin_src emacs-lisp
-    (defun cache-result (fun &rest r)
-    (let ((c (assoc (cons fun r) cache)))
-      (if c (cdr c)
-        (let ((res (apply fun r)))
-    	(push (cons (cons fun r) res) cache)
-    	res ))))
+      (defun cache-result (fun &rest r)
+      (let ((c (assoc (cons fun r) cache)))
+        (if c (cdr c)
+          (let ((res (apply fun r)))
+      	(push (cons (cons fun r) res) cache)
+      	res ))))
+
+      (defun memoize (fun)
+        (setq cache nil)
+        (advice-add fun :around 'cache-result))
   #+end_src

p10/p10.org

@@ -2,7 +2,7 @@
 
 #+begin_src emacs-lisp :results none
   (with-temp-buffer
-    (insert-file-contents "input-test")
+    (insert-file-contents "input")
     (advent/replace-multiple-regex-buffer
      '(("," . " ")
        ("^" . "(")
@@ -47,4 +47,65 @@ for part 1 we do not need the last item
 #+end_src
 
 #+RESULTS:
-: 7
+: 404
+
+This approach blows the stack
+#+begin_src emacs-lisp
+  (setq machines (--map (-rotate 1 (cdr it)) data))
+
+  (defun apply-button (joltage button)
+    (--map-indexed (if (-contains-p button it-index) (- it 1) it) joltage))
+
+  (defun good-buttons (machine)
+    (-filter (lambda (button) (--every (< 0 (nth it (car machine))) button)) (cdr machine)))
+
+  (defun solve-machines (machines)
+    (-mapcat (lambda (machine)
+  	     (if (= 0 (-sum (car machine))) (list machine)
+  	       (--map (cons it (cdr machine)) (--map (apply-button (car machine) it) (good-buttons machine)))))
+  	    machines ))
+
+  (-iterate 'solve-machines (list (car machines)) 19)
+
+#+end_src
+
+Instead, go depth first and memoize for the win
+#+begin_src emacs-lisp
+  (setq machines (--map (-rotate 1 (cdr it)) data)
+        machines (--map (cons (car it) (--sort (> (length it) (length other)) (cdr it))) machines))
+
+  (defun apply-button (joltage button)
+    (--map-indexed (if (-contains-p button it-index) (- it 1) it) joltage))
+
+    (defun good-buttons (machine)
+      (-filter (lambda (button) (--every (< 0 (nth it (car machine))) button)) (cdr machine)))
+
+    (defun or-min (l)
+      (when l (-min l)))
+
+    (defun nil-1+ (l)
+      (when l (1+ l)))
+
+    (defun solve-machine (machine)
+      (when machine
+        (if (= 0 (-sum (car machine))) 0
+  	(nil-1+ (solve-machine (-first 'solve-machine (--map (cons it (cdr machine)) (--map (apply-button (car machine) it) (good-buttons machine)))))))))
+
+    (memoize 'solve-machine)
+  (let ((a))
+  (setq num 0
+  	res nil)
+  (--each machines (progn (message (format "%d" (setq num (1+ num))))
+  			(push (solve-machine it) res)))
+  (-sum res))
+
+  (cadr machines)
+  (solve-machine (cadr machines))
+  (length machines)151
+#+end_src
+
+#+RESULTS:
+: 33
+
+
+