p12.1

p10/p10.org

@@ -56,7 +56,6 @@ This yields the coordinates of the trailheads
 		    (-mapcat #'identity
 			     (-map-indexed (lambda (y l) (-map-indexed (lambda (x el) (list el (list x y))) l)) data-heights)))))
 #+end_src
-
 #+RESULTS:
 |  2 |  0 |
 | 14 |  0 |

p12/p12.org

@@ -4,7 +4,7 @@ Load the file into a list of lines
 #+begin_src emacs-lisp
 (require 'dash)
   (with-temp-buffer
-    (insert-file-contents "input-test")
+    (insert-file-contents "input")
     (goto-char (point-min))
     (replace-regexp "^" "\"")
        (goto-char (point-min))
@@ -27,22 +27,63 @@ and split into a list of list of chars
 #+end_src
 
 #+RESULTS:
-: 10
+: 140
 
-#+begin_src emacs-lisp
-    (defun acceptable-p (p)
-      (let ((x (car p))
-        (y (cadr p)))
-    (and (>= x 0) (>= y 0) (< x width) (< y height)) ))
+#+begin_src emacs-lisp :results silent
+  (defun acceptable-p (p)
+    (let ((x (car p))
+	  (y (cadr p)))
+      (and (>= x 0) (>= y 0) (< x width) (< y height)) ))
 
-    (defun neighbours (p)
-      (let ((x (car p))
-        (y (cadr p)))
-        (-map (lambda (q) (list (+ x (car q)) (+ y (cadr q)))) '((+1 0) (-1 0) (0 1) (0 -1)))))
+  (defun neighbours (p)
+    (let ((x (car p))
+	  (y (cadr p)))
+      (-map (lambda (q) (list (+ x (car q)) (+ y (cadr q)))) '((+1 0) (-1 0) (0 1) (0 -1)))))
 
   (defun acceptable-neighbours (p)
-      (-filter #'acceptable-p (neighbours p)))
+    (-filter #'acceptable-p (neighbours p)))
+
+  (defun plant (p)
+    (if (not (acceptable-p p)) ?. 
+      (nth (car p) (nth (cadr p) data-chars))))
+#+end_src
+
+collect all plants type and return a list of list of positions
+
+now we need to split each group into regions
+ACC is a list of regions. The function  
+#+begin_src emacs-lisp :results none
+  (defun agglomerate (acc el)
+    (let ((nbhs (acceptable-neighbours el)))
+      (cons (-mapcat #'identity (cons (list el) (--filter (-intersection it nbhs) acc))) 
+	    (--filter (not (-intersection it nbhs)) acc))
+      )
+    )
+
+  (setq regions (--mapcat (-reduce-from #'agglomerate nil it) groups))
+#+end_src
+
+#+begin_src emacs-lisp
+    (defun count-fence (el)
+      (let ((i (plant el))
+	    (pos el))
+	(length (--filter (not (eq i it)) (-map #'plant (neighbours pos))))))
 
-  (defun height (p)
-    (nth (car p) (nth (cadr p) data-heights)))
+    (defun count-vertices (el)
+      
+      )
+  (-reduce #'+  (--map (* (car it) (cdr it))
+		       (-zip-pair (-map #'length regions)
+				  (-map (lambda (region) (-reduce #'+ (-map #'count-fence region))) regions))))
 #+end_src
+
+#+RESULTS:
+: 1451030
+
+
+#+begin_src emacs-lisp :no-results
+  (setq areas (-frequencies (-mapcat #'identity data-chars)))
+#+end_src
+
+
+(plant ' (0 9))