72 lines
2.3 KiB
Common Lisp
72 lines
2.3 KiB
Common Lisp
;;; https://adventofcode.com/2022/day/4
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;; so, just read two intervals.
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;; intervals , separated, two numbers - separated.
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;; so. ugh. have a parsing function. maybe ask how to better parse
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;; then to calculate "total inclusion" - can go both ways, so 4 checks
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(setq test-line "2-4,6-8")
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(setq test-line "2-8,3-7")
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(require 'cl-ppcre)
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;; (cl-ppcre:split "(\\ )" line :with-registers-p nil)
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(setq intervals (mapcar #'parse-integer (cl-ppcre:split "(,|-)" test-line)))
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(defun line-to-nums (line)
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(mapcar #'parse-integer (cl-ppcre:split "(,|-)" line)))
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(defun first-includes-second (l1 r1 l2 r2)
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(and (<= l1 l2) (>= r1 r2)))
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(first-includes-second 2 8 3 7)
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(first-includes-second 3 8 3 7)
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(first-includes-second 4 8 3 7)
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(defun first-or-last-includes-another (l1 r1 l2 r2)
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(or (first-includes-second l1 r1 l2 r2)
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(first-includes-second l2 r2 l1 r1)))
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(with-open-file (in-file "day4-test-input.txt")
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(let ((running-count 0))
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(loop
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for line = (read-line in-file nil nil)
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while line
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do (if (apply #'first-or-last-includes-another (line-to-nums line))
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(incf running-count 1))
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finally (return running-count))))
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(defun count-full-interlaps (filename)
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(with-open-file (in-file filename)
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(let ((running-count 0))
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(loop
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for line = (read-line in-file nil nil)
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while line
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do (if (apply #'first-or-last-includes-another (line-to-nums line))
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(incf running-count 1))
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finally (return running-count)))))
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(count-full-interlaps "day4-test-input.txt")
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(count-full-interlaps "day4-input.txt")
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;; next part - count intervals that "overlap at all", even if by single point
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;; could count 'not overlapping' - should be very easy
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;; and count total, and deduct
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(defun count-any-overlap (filename)
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(with-open-file (in-file filename)
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(let ((running-count-non-overlap 0)
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(total-count 0))
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(loop
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for line = (read-line in-file nil nil)
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while line
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do (let ((nums (line-to-nums line)))
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(if (or (< (second nums) (third nums))
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(< (fourth nums) (first nums)))
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(incf running-count-non-overlap 1))
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(incf total-count 1)
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)
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finally (return (- total-count running-count-non-overlap))))))
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(count-any-overlap "day4-test-input.txt")
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(count-any-overlap "day4-input.txt")
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