src/2017/days/day-01.lisp @ 2848a4548adf
2023/01 and 2022/01 Also start porting my test data to the new account, since Twitter imploded and apparently it's impossible for a website to store a goddamn username and password in The Year of Our Lord 2023 so everyone just outsources auth all the time, ugh.
| author | Steve Losh <steve@stevelosh.com> |
|---|---|
| date | Fri, 01 Dec 2023 11:05:43 -0500 |
| parents | 182bdd87fd9e |
| children | (none) |
(advent:defpackage* :advent/2017/01) (in-package :advent/2017/01) (define-problem (2017 1) (data read-line) (1049 1508) (iterate (with digits = (map 'vector #'digit-char-p data)) (for digit :in-vector digits) (for prev :previous digit :initially (aref digits (1- (length digits)))) (for j :modulo (length digits) :from (truncate (length digits) 2)) (for next = (aref digits j)) (when (= digit prev) (sum digit :into part1)) (when (= digit next) (sum digit :into part2)) (finally (return (values part1 part2)))))