125 lines
2.4 KiB
Common Lisp
125 lines
2.4 KiB
Common Lisp
(defpackage :aoc/2024/05
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(:use :cl :aoc :alexandria :trivia)
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(:export
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#:sample-data
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#:sample-data2
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#:part1
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#:part2
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#:rule-okp
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#:rules-okp
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#:middle-page
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#:apply-rule
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#:sort-with-rules
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))
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(in-package :aoc/2024/05)
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(defun parse-rule (s)
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(mapcar #'parse-integer (cl-ppcre:split "[|]" s)))
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(defun parse-book (s)
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(mapcar #'parse-integer (cl-ppcre:split "," s)))
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(defun parse-input (lines)
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(let ((sep (position "" lines :test #'equal)))
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(list
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(mapcar #'parse-rule (subseq lines 0 sep ))
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(mapcar #'parse-book (subseq lines (1+ sep))))))
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(defvar input-data '())
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(setf input-data (parse-input (test-input 2024 5)))
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(defvar sample-text "")
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(setf sample-text (aoc:split-lines "47|53
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97|13
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97|61
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97|47
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75|29
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61|13
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75|53
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29|13
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97|29
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53|29
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61|53
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97|53
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61|29
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47|13
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75|47
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97|75
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47|61
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75|61
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47|29
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75|13
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53|13
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75,47,61,53,29
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97,61,53,29,13
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75,29,13
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75,97,47,61,53
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61,13,29
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97,13,75,29,47"))
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(defvar sample-data '())
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(setf sample-data (parse-input sample-text))
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(defun rule-okp (rule book)
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(let ((a (or (position (first rule) book) -1))
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(b (or (position (second rule) book) 999)))
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(< a b)))
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(defun rules-okp (rules book)
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(every (lambda (rule) (rule-okp rule book)) rules))
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(defun middle-page (book)
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(let ((mid (floor (/ (length book) 2))))
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(nth mid book)))
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(defun sum-middle-pages (data)
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(let* ((rules (first data))
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(books (second data)))
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(loop for book in books
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if (rules-okp rules book)
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sum (middle-page book))))
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(defun part1 (data)
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(format nil "~A" (sum-middle-pages data)))
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(defun apply-rule (book rule)
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(let ((a (position (first rule) book))
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(b (position (second rule) book)))
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(cond
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((not a) book)
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((not b) book)
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((< a b)
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book)
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(t (append (subseq book 0 b)
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(subseq book a (1+ a))
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(subseq book b a)
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(subseq book (1+ a))))
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)))
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(defun sort-with-rules (rules book)
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(let ((sorted-book (reduce #'apply-rule rules :initial-value book)))
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(if (equal sorted-book book)
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book
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(sort-with-rules rules sorted-book))))
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(defun fixed-books (data)
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(let ((rules (first data))
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(books (second data)))
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(loop for book in books
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if (not (rules-okp rules book))
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collect (sort-with-rules rules book))))
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(defun part2 (data)
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(let ((s (loop for book in (fixed-books data)
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sum (middle-page book))))
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(format nil "~A" s)))
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(defun solve-day ()
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(format t "part1: ~A~%" (part1 input-data))
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(format t "part2: ~A~%" (part2 input-data)))
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