[p5] Part 2 done

p5/p5.org

@@ -3,7 +3,7 @@
 First load the data as a list of cons cells (start . end)
 #+begin_src emacs-lisp :results none
   (with-temp-buffer
-    (insert-file-contents "input-test")
+    (insert-file-contents "input")
     (advent/replace-multiple-regex-buffer
      '(
        ("^\\([0-9]*\\)-\\([0-9]*\\)$" . "(\\1 . \\2)")
@@ -15,16 +15,31 @@ First load the data as a list of cons cells (start . end)
     (eval-buffer))
 #+end_src
 
+This is for part 1
 #+begin_src emacs-lisp
-  (length 
+  (length
    (-filter (lambda (id)
   	    (--any (and (>= id (car it))
   			(<= id (cdr it)))
 #+end_src
 
+For part 2, sort and merge the ranges (when they are overlapping or
+adjacent), then sum their lengths
 #+begin_src emacs-lisp
   (setq sorted-ranges (--sort (< (car it) (car other)) ranges))
+
+  (defun merge-ranges (li)
+    (-reduce (lambda (a b)
+               (let* ((a (if (listp (cdr a)) a (list a)))
+                      (aa (car a)))
+                 (if (>= (1+ (cdr aa)) (car b))
+                     (cons (cons (car aa) (max (cdr aa) (cdr b))) (cdr a))
+                   (cons b a))))
+             li))
+
+  (-sum (--map (- (cdr it) (car it) -1)
+               (merge-ranges sorted-ranges)))
 #+end_src
-#+RESULTS:
-: 744
 
+#+RESULTS:
+: 347468726696961