Commit | Line | Data |
---|---|---|
c5ac16de JK |
1 | (asdf:load-system :adventofcode2020) |
2 | (in-package #:adventofcode2020) | |
3 | ||
4 | (defun calc-seat (seat-spec) | |
5 | (let ((row (string-right-trim "RL" seat-spec)) | |
6 | (col (string-left-trim "FB" seat-spec)) | |
7 | (convert-to-int | |
8 | (lambda (str one) | |
9 | (loop with len = (1- (length str)) | |
10 | for c across str | |
11 | for i downfrom len | |
12 | summing (if (char= c one) | |
13 | (ash 1 i) 0))))) | |
14 | (mapcar convert-to-int (list row col) '(#\B #\R)))) | |
15 | ||
16 | (defun calc-seat-id (row-col) | |
17 | (destructuring-bind (row col) row-col | |
18 | (+ (* row 8) col))) | |
19 | ||
20 | (day 05 input | |
21 | (let* ((lines (list-from input)) | |
22 | (seat-ids (-<>> lines | |
23 | (mapcar (compose #'calc-seat-id #'calc-seat)) | |
24 | (sort <> #'>)))) | |
25 | (part1 (first seat-ids)) | |
26 | (part2 (loop for big in seat-ids | |
27 | for small in (cdr seat-ids) | |
28 | when (= small (- big 2)) | |
29 | return (1+ small))))) | |
30 | ||
31 | (def-suite day05) | |
32 | (in-suite day05) | |
33 | ||
34 | (test calc-seats | |
35 | (is (equal | |
36 | '((44 5) (70 7) (14 7) (102 4)) | |
37 | (mapcar #'calc-seat '("FBFBBFFRLR" "BFFFBBFRRR" | |
38 | "FFFBBBFRRR" "BBFFBBFRLL"))))) | |
39 | ||
40 | (run! 'day05) |