| 1 | (in-package #:adventofcode2020) |
| 2 | |
| 3 | ;;; Utility functions |
| 4 | |
| 5 | (defun list-from (str) |
| 6 | (split "\\n" str)) |
| 7 | |
| 8 | (defun int-list-from (str) |
| 9 | (mapcar #'parse-integer (list-from str))) |
| 10 | |
| 11 | (defun cartesian-product (A B &rest C) |
| 12 | (let ((helper (lambda (X Y) |
| 13 | (if Y (loop for x in X |
| 14 | nconc (loop for y in Y |
| 15 | collecting (append x (list y)))) |
| 16 | X))) |
| 17 | (wrap-A (mapcar #'list A))) |
| 18 | (reduce helper C :initial-value (funcall helper wrap-A B)))) |
| 19 | |
| 20 | (def-suite util) |
| 21 | (in-suite util) |
| 22 | |
| 23 | (test cart-prod-2 |
| 24 | (is (equal |
| 25 | '((a a) (a b) (b a) (b b)) |
| 26 | (cartesian-product '(a b) '(a b))))) |
| 27 | |
| 28 | (test cart-prod-3 |
| 29 | (is (equal |
| 30 | '((a a a) (a a b) (a b a) (a b b) |
| 31 | (b a a) (b a b) (b b a) (b b b)) |
| 32 | (cartesian-product '(a b) '(a b) '(a b))))) |
| 33 | |
| 34 | (test cart-prod-4 |
| 35 | (is (equal |
| 36 | '((a a a a) (a a a b) (a a b a) (a a b b) (a b a a) (a b a b) (a b b a) (a b b b) |
| 37 | (b a a a) (b a a b) (b a b a) (b a b b) (b b a a) (b b a b) (b b b a) (b b b b)) |
| 38 | (cartesian-product '(a b) '(a b) '(a b) '(a b))))) |
| 39 | |
| 40 | |