46 lines
1.0 KiB
Scheme
46 lines
1.0 KiB
Scheme
(define (get-word text-port)
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(let loop [(w '())]
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(let [(c (get-char text-port))]
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(if (or (eof-object? c) (char-whitespace? c))
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(list->string (reverse w))
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(loop (cons c w))))))
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(call-with-input-file
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"input"
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(lambda (file)
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(let loop [(x 0) (y 0)]
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(let [(amount (string->number (get-word file)))
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(move (get-word file))]
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(cond
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((string=? move "forward")
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(loop (+ x amount) y))
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((string=? move "down")
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(loop x (+ y amount)))
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((string=? move "up")
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(loop x (- y amount)))
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(else
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(display "part 1: ")
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(display (* x y))
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(newline)))))))
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(call-with-input-file
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"input"
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(lambda (file)
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(let loop [(x 0) (y 0) (aim 0)]
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(let [(amount (string->number (get-word file)))
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(move (get-word file))]
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(cond
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((string=? move "forward")
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(loop
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(+ x amount)
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(+ y (* aim amount))
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aim))
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((string=? move "down")
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(loop x y (+ aim amount)))
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((string=? move "up")
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(loop x y (- aim amount)))
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(else
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(display "part 2: ")
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(display (* x y))
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(newline)))))))
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