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September 2017 Update

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Ingy döt Net 2017-09-23 10:01:46 +02:00
parent bba7bfd280
commit ba8067c3b7
14570 changed files with 153136 additions and 63871 deletions
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42
Task/Fibonacci-word/Scheme/fibonacci-word.ss Normal file
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(import (scheme base)
(scheme inexact)
(scheme write))
(define *words* (make-vector 38 ""))
(define (create-words)
(vector-set! *words* 1 "1")
(vector-set! *words* 2 "0")
(do ((i 3 (+ 1 i)))
((= i (vector-length *words*)) )
(vector-set! *words* i (string-append (vector-ref *words* (- i 1))
(vector-ref *words* (- i 2))))))
;; in this context, word only contains 1 or 0
(define (entropy word)
(let* ((N (string-length word))
(num-ones 0)
(num-zeros 0))
(string-for-each (lambda (c)
(if (char=? c #\1)
(set! num-ones (+ 1 num-ones))
(set! num-zeros (+ 1 num-zeros))))
word)
(if (or (zero? num-ones) (zero? num-zeros))
0
(- 0
(* (/ num-ones N) (log (/ num-ones N) 2))
(* (/ num-zeros N) (log (/ num-zeros N) 2))))))
;; display values
(create-words)
(do ((i 1 (+ 1 i)))
((= i (vector-length *words*)) )
(display (string-append (number->string i)
" "
(number->string
(string-length (vector-ref *words* i)))
" "
(number->string
(entropy (vector-ref *words* i)))
"\n")))