src/2018/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/2018/01) (in-package :advent/2018/01) (define-problem (2018 1) (data read-all) (522 73364) (values (summation data) (progn (setf (cdr (last data)) data) ; make data a circular list for easy looping (iterate (with seen = (make-hash-set :initial-contents '(0))) (for number :in data) (summing number :into frequency) (if (hset-contains-p seen frequency) (return frequency) (hset-insert! seen frequency))))))