50 lines
1.4 KiB
Racket
50 lines
1.4 KiB
Racket
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#lang racket
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(define input (for/list ([str (string-trim (file->string "input.8.txt"))])
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(string->number (string str))))
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(define width 25)
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(define height 6)
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(define pixels-per-layer (* width height))
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(define (make-chunks lst n)
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(cond [(empty? lst) '()]
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[else (cons (take lst n) (make-chunks (drop lst n) n))]))
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(define layers (make-chunks input pixels-per-layer))
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(define (count-occur lst what)
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(length (filter ((curry =) what) lst)))
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(define (lowest-zeroes chunks)
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(cond [(empty? (rest chunks)) (first chunks)]
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[else
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(let ([this (first chunks)]
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[next (lowest-zeroes (rest chunks))])
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(if (< (count-occur this 0) (count-occur next 0))
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this
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next))]))
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(define lowest-zero-layer (lowest-zeroes layers))
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;; Part 1
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(* (count-occur lowest-zero-layer 1) (count-occur lowest-zero-layer 2))
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(require 2htdp/image)
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(define pixel-size 16)
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(define colors '(black white transparent))
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(define (render-pixel code)
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(rectangle pixel-size pixel-size 'solid (list-ref colors code)))
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(define (render-layer layer)
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(define (render-row row)
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(apply beside (map render-pixel row)))
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(apply above (map render-row (make-chunks layer width))))
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(define base (empty-scene (* pixel-size width) (* pixel-size height)))
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(define decoded-image
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(foldr overlay base (map render-layer layers)))
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;; Part 2
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(frame decoded-image)
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