commit e33c3158235bd13fee0db1b4eaa5a70bd4686b25 parent 1fa3f18602dc9132a51f0bf72ed96f6c773b04c1 Author: Lukas Henkel <lh@entf.net> Date: Sat, 3 Dec 2022 10:29:48 +0100 Refactored loops Diffstat:
| M | src/day03.lisp | | | 64 | ++++++++++++++++++++++++++-------------------------------------- |
1 file changed, 26 insertions(+), 38 deletions(-)
diff --git a/src/day03.lisp b/src/day03.lisp @@ -9,46 +9,34 @@ (defun task1 (inputs) (loop for input in inputs - sum (let* ((compartment-size (/ (length input) 2)) - (compartment1 (subseq input 0 compartment-size)) - (compartment2 (subseq input compartment-size)) - (result)) - (loop for item1 across compartment1 - for item2 across compartment2 - when (find item1 compartment2) - do (progn - (setf result item1) - (loop-finish)) - when (find item2 compartment1) - do (progn - (setf result item2) - (loop-finish))) - (calculate-priority result)))) - -(defun all-chars-from-to (from to) - (loop for i from (char-code from) to (char-code to) - collect (code-char i))) + sum (loop with compartment-size = (/ (length input) 2) + with compartment1 = (subseq input 0 compartment-size) + with compartment2 = (subseq input compartment-size) + with use-item2 = nil + for item1 across compartment1 + for item2 across compartment2 + until (or + (find item1 compartment2) + (and + (find item2 compartment1) + (setf use-item2 t))) + finally (return + (calculate-priority (if use-item2 item2 item1)))))) (defun task2 (inputs) - (let* ((items (concatenate 'list - (all-chars-from-to #\A #\Z) - (all-chars-from-to #\a #\z))) - (group) - (groups (loop for i from 1 - for elf in inputs - do (push elf group) - when (= (mod i 3) 0) - collect group and do (setf group nil)))) - (loop for group in groups - sum (let ((result)) - (loop for item in items - when (= 0 (length (remove-if (lambda (elf) - (find item elf)) - group))) - do (progn - (setf result item) - (loop-finish))) - (calculate-priority result))))) + (loop with length = (length inputs) + for start from 0 + for end = (+ start 3) + while (<= end length) + when (= 0 (mod end 3)) + sum (loop for item = #\A then (cond ((char= item #\Z) #\a) + ((char= item #\z) nil) + (t (code-char (1+ (char-code item))))) + while item + while (remove-if (lambda (elf) + (find item elf)) + (subseq inputs start end)) + finally (return (calculate-priority item))))) (define-day 3 ()