13 lines
423 B
Racket
13 lines
423 B
Racket
#lang racket
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(require "hs.rkt")
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(define N 100000)
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(define t (make-hasheq))
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(define best
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(for/fold ([best #f]) ([i (in-range 1 (add1 N))])
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(define len (length (hailstone i)))
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(define freq (add1 (hash-ref t len 0)))
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(hash-set! t len freq)
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(if (and best (> (car best) freq)) best (cons freq len))))
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(printf "Most frequent sequence length for x<=~s: ~s, appearing ~s times\n" N
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(cdr best) (car best))
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