diff options
Diffstat (limited to '2024/puzzle-3.lisp')
| -rw-r--r-- | 2024/puzzle-3.lisp | 39 |
1 files changed, 20 insertions, 19 deletions
diff --git a/2024/puzzle-3.lisp b/2024/puzzle-3.lisp index cca2f43..46b2902 100644 --- a/2024/puzzle-3.lisp +++ b/2024/puzzle-3.lisp @@ -3,19 +3,19 @@ (defparameter input (uiop:read-file-string "3-input")) (defun is-good-mul (str) - (let* ((delimiter (search "," str)) - (end (search ")" str))) - (if (or (null delimiter) (null end) - (> delimiter end) - (not (eq #\( (char str 3)))) - nil - (let* ((first-arg (subseq str 4 delimiter)) - (second-arg (subseq str (1+ delimiter) end))) - (and (every #'digit-char-p first-arg) - (every #'digit-char-p second-arg)))))) - -(defun trim-mul (str) - (subseq str 0 (1+ (search ")" str)))) + (let ((start (search "(" str)) + (middle (search "," str)) + (end (search ")" str))) + (and (not (null start)) (not (null middle)) (not (null end)) + ;; mul( <- 3 character + (eq start 3) + ;; Simple to understand + (< start end) + (< start middle) + (< middle end) + ;; Make sure the arguments are purely numbers + (every #'digit-char-p (subseq str (1+ start) middle)) + (every #'digit-char-p (subseq str (1+ middle) end))))) (defun parse-mul (str) (let ((start (search "(" str)) @@ -28,9 +28,11 @@ (let ((possible (search-all "mul" line))) (--> (cdr possible) (append _ (list (length line))) + ;; index of mul -> (position substring) (mapcar (lambda (z1 z2) (cons z1 (subseq line z1 z2))) possible _) + ;; remove any bad muls (remove-if-not (lambda (x) (is-good-mul (cdr x))) _) - (mapcar (lambda (x) (cons (car x) (trim-mul (cdr x)))) _) + ;; parse muls (mapcar (lambda (x) (cons (car x) (parse-mul (cdr x)))) _)))) (format t "Round 1: ~a~%" @@ -40,11 +42,10 @@ (defun parse-input-conds (input) (let ((dos (search-all "do()" input)) (donts (search-all "don't()" input))) - (cons - '(do . 0) - (sort (append (mapcar (lambda (x) (cons 'do x)) dos) - (mapcar (lambda (x) (cons 'dont x)) donts)) - (lambda (x y) (< (cdr x) (cdr y))))))) + (--> (append (mapcar (lambda (x) (cons 'do x)) dos) + (mapcar (lambda (x) (cons 'dont x)) donts)) + (sort _ (lambda (x y) (< (cdr x) (cdr y)))) + (cons '(do . 0) _)))) (defun current-cond (pos conds) (caar (last (remove-if (lambda (x) (> (cdr x) pos)) conds)))) |