#+title: Solution to p10 #+begin_src emacs-lisp :results none (with-temp-buffer (insert-file-contents "input-test") (advent/replace-multiple-regex-buffer '(("," . " ") ("^" . "(") ("$" . ")") ("\\[" . "\"") ("\\]" . "\"") ("{" . "(") ("}" . ")") )) (goto-char (point-min)) (insert "(setq data '(") (goto-char (point-max)) (insert "))") (eval-buffer)) #+end_src #+begin_src emacs-lisp :results none (defun zero-one (n) (if (eq n ?#) 1 0)) (setq cleanedup-data (--map (cons (-map #'zero-one (advent/split-string-into-char-list (car it))) (cdr it)) data)) #+end_src for part 1 we do not need the last item #+begin_src emacs-lisp (setq machines (--map (-drop-last 1 it) cleanedup-data)) (defun to-bin (l) (-sum (--map-indexed (* it (expt 2 it-index)) l))) (defun to-mask (l) (-sum (--map (expt 2 it) l))) (setq mask-machines (--map (cons (to-bin (car it)) (-map #'to-mask (cdr it))) machines)) (-sum (-map (lambda (machine) (-min (-map 'length (--filter (= (car machine) (apply 'logxor it)) (-powerset (cdr machine)))))) mask-machines)) #+end_src #+RESULTS: : 7