From 41369513754bef0d576638df115e214eb5629942 Mon Sep 17 00:00:00 2001
From: Oscar Najera <hi@oscarnajera.com>
Date: Mon, 4 Dec 2023 02:20:07 +0100
Subject: refactor day03
---
AoC2023/day03/solver.lisp | 70 +++++++++++++----------------------------------
1 file changed, 19 insertions(+), 51 deletions(-)
diff --git a/AoC2023/day03/solver.lisp b/AoC2023/day03/solver.lisp
index 6f9c799..b326a88 100644
--- a/AoC2023/day03/solver.lisp
+++ b/AoC2023/day03/solver.lisp
@@ -18,67 +18,35 @@
(and (<= 0 row row-max)
(<= 0 col col-max)))))
-(defun contour (row start end)
- (list*
- (cons row (1- start))
- (cons row end)
- (loop for i from (1- start) to end
- collect (cons (1- row) i)
- collect (cons (1+ row) i))))
-
-(defun is-relevant (limits rows)
- (lambda(row start end)
- (some
- (lambda (cell)
- (and (funcall limits cell)
- (destructuring-bind (row . col) cell
- (let ((char (aref (aref rows row) col)))
- (not (or (digit-char-p char)
- (eq #\. char)))))))
- (contour row start end))))
+(defun in-line-numbers (line symbol-pos)
+ (loop for (num-start num-end) on (cl-ppcre:all-matches "\\d+" line) by #'cddr
+ when (<= (1- num-start) symbol-pos num-end)
+ collect (parse-integer (subseq line num-start num-end))))
+(defun adjacent-numbers (rows row limits symbol-pos)
+ (loop for y in (list (1- row) row (1+ row))
+ when (funcall limits (cons y symbol-pos))
+ nconc (in-line-numbers (aref rows y) symbol-pos)))
-(defun solver1 (lines)
+(defun solver (lines symbol-regex reducer)
(let* ((rows (make-array (length lines) :initial-contents lines
:adjustable t))
(limits (inbounds (1- (length lines))
- (1- (length (car lines)))))
- (keep (is-relevant limits rows))
- (sum 0))
+ (1- (length (car lines))))))
(loop for row below (length lines)
- for content = (aref rows row) do
- (cl-ppcre:do-scans (start end _rs _re "\\d+" content)
- (when (funcall keep row start end)
- ;; (format t "~a ~a ~a~%" start end (subseq content start end))
- (incf sum (parse-integer (subseq content start end))))))
- sum))
-
+ sum (loop for (start _end) on (cl-ppcre:all-matches symbol-regex (aref rows row)) by #'cddr
+ sum (funcall reducer (adjacent-numbers rows row limits start))))))
-(defun adjacent-numbers (line gear-start)
- (loop for (num-start num-end) on (cl-ppcre:all-matches "\\d+" line) by #'cddr
- when (<= (1- num-start) gear-start num-end)
- collect (parse-integer (subseq line num-start num-end))))
+(defun solver1 (lines)
+ (solver lines "[^.\\d]" (lambda (numbers) (apply #'+ numbers))))
(defun solver2 (lines)
- (let* ((rows (make-array (length lines) :initial-contents lines
- :adjustable t))
- (limits (inbounds (1- (length lines))
- (1- (length (car lines)))))
- (sum 0))
- (loop for row below (length lines)
- for content = (aref rows row) do
- (loop for (gear-start end) on (cl-ppcre:all-matches "\\*" content) by #'cddr do
- (let ((ratios
- (append
- (when (funcall limits (cons (1- row) gear-start))
- (adjacent-numbers (aref rows (1- row)) gear-start))
- (adjacent-numbers content gear-start)
- (when (funcall limits (cons (1+ row) gear-start))
- (adjacent-numbers (aref rows (1+ row)) gear-start)))))
- (when (= 2 (length ratios))
- (incf sum (* (car ratios) (cadr ratios)))))))
- sum))
+ (solver lines "\\*"
+ (lambda (ratios)
+ (if (= 2 (length ratios))
+ (* (car ratios) (cadr ratios))
+ 0))))
(fiveam:test solutions
(fiveam:is (= 4361 (solver1 (uiop:split-string eg-input :separator '(#\Newline)))))
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