Cleanup solution to p14

p14/p14.org

@@ -1,6 +1,7 @@
 #+title: Solution to p14
-First parse with regex to make into a list
-#+begin_src emacs-lisp
+
+First parse with a regex to make into a list
+#+begin_src emacs-lisp :results none
   (require 'dash)
   (with-temp-buffer
       (insert-file-contents "input-test")
@@ -11,35 +12,32 @@ First parse with regex to make into a list
       (insert "(setq data '(")
       (goto-char (point-max))
       (insert "))")
-      (write-file "tmp"))
 #+end_src
 
-    #+RESULTS:
-
+Implement the flow on the torus
 #+begin_src emacs-lisp
   (defun move (p v time)
     (list (mod (+ (car p) (* time (car v))) w)
           (mod (+ (cadr p) (* time (cadr v))) h)))
+
   (setq newpos (--map (move (car it) (cadr it) 100) data))
-  (defun quadrant (comp p)
+
+  (defun quadrant-p (comp p)
     (and (funcall (car comp) (car p) (floor (* w 0.5)))
      (funcall (cadr comp) (cadr p) (floor (* h 0.5)))))
-    (-reduce '* (--map (length (-filter (lambda (x) (quadrant it x)) newpos)) '((< <) (< >) (> <) (> >)))))
+
+    (-reduce '* (--map (length (-filter (lambda (x) (quadrant-p it x))
+                                        newpos))
+                       '((< <) (< >) (> <) (> >)))))
 #+end_src
 
 #+RESULTS:
 : 231852216
 
-the second part is... meh. try and filter frames and check them
-by some properties
-#+begin_src emacs-lisp :results none
-  (defun flip (p)
-    (list (- w (car p) 1) (cadr p)))
-  (defun symmetric-p (li)
-    (eq (length (-intersection li (-map #'flip li))) (length li)))
-#+end_src
-
-
+the second part is... meh. try and filter frames and check them by
+some properties; for instance we could check for a long enough
+horizontal line.  Save the frames in plain text and then we can use
+grep later
 #+begin_src emacs-lisp
   (defun make-bg ()
      (insert (apply #'concat (-repeat h (concat (concat (-repeat w ?. )) "\n")))))