[p9] Part 1 done

p9/p9.org

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+#+title: Solution to p9
+
+#+begin_src emacs-lisp :results none
+  (with-temp-buffer
+    (insert-file-contents "input")
+    (advent/replace-multiple-regex-buffer
+     '(("," . " ")
+       ("^" . "(")
+       ("$" . ")")))
+    (goto-char (point-min))
+    (insert "(setq data '(")
+    (goto-char (point-max))
+    (insert "))")
+    (eval-buffer))
+#+end_src
+
+Find max area
+#+begin_src emacs-lisp 
+  (defun area (el)
+    (let ((a (car el))
+  	(b (cdr el)))
+      (abs (* (- (car a) (car b) -1)
+  	    (- (cadr a) (cadr b) -1)))))
+
+  (defun symmetric-pairs (list)
+   (apply #'append (--map-indexed (-map (lambda (other) (cons it other))
+                         (-drop (1+ it-index) list))
+                   list)))
+
+  (-max (-map 'area (symmetric-pairs data)))
+#+end_src
+
+#+RESULTS:
+: 4737096935
+