src/2020/days/day-03.lisp @ 08dd2b57f2c0
2021/03
| author | Steve Losh <steve@stevelosh.com> |
|---|---|
| date | Fri, 03 Dec 2021 12:36:07 -0500 |
| parents | ff7c8ed35992 |
| children | (none) |
(advent:defpackage* :advent/2020/03) (in-package :advent/2020/03) (defun count-trees (world drow dcol) (destructuring-bind (rows cols) (array-dimensions world) (iterate (for row :from 0 :below rows :by drow) (for col :modulo cols :from 0 :by dcol) (counting (char= #\# (aref world row col)))))) (define-problem (2020 3) (data read-2d-array) (257 1744787392) (values (count-trees data 1 3) (* (count-trees data 1 1) (count-trees data 1 3) (count-trees data 1 5) (count-trees data 1 7) (count-trees data 2 1)))) #; Scratch --------------------------------------------------------------------