Rename for easier ctrlping
author |
Steve Losh <steve@stevelosh.com> |
date |
Sun, 16 Dec 2018 18:11:25 -0500 |
parents |
src/2018/02.lisp@75998992ab3c |
children |
a19c9e1fd077 |
(defpackage :advent/2018/02 #.cl-user::*advent-use*)
(in-package :advent/2018/02)
(named-readtables:in-readtable :interpol-syntax)
(define-problem (2018 2) (data read-lines)
(values
(let* ((freqs (mapcar #'frequencies data))
(counts (mapcar #'hash-table-values freqs)))
(* (count 2 counts :test #'member)
(count 3 counts :test #'member)))
;; just brute force it
(multiple-value-bind (a b)
(iterate
(for (a . remaining) :on data)
(for b = (find 1 remaining :key (curry #'hamming-distance a)))
(when b
(return (values a b))))
(let ((i (mismatch a b)))
(str:concat (subseq a 0 i)
(subseq a (1+ i)))))))