Petar Kapriš
a697f52405
To be noted: the drawing in exercise 1.14 is unfinished. I did it in a notebook, but haven't yet had the time to put it in a txt file.
26 lines
709 B
Scheme
26 lines
709 B
Scheme
#lang sicp
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(define (square x) (* x x))
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;(define (next x)
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; (if (= x 2)
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; 3
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; (+ x 2)))
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(define (next x) (+ x 1))
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(define (smallest-divisor n)
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(find-divisor n 2))
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(define (find-divisor n test-divisor)
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(cond ((> (square test-divisor) n) n)
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((divides? test-divisor n) test-divisor)
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(else (find-divisor n (next test-divisor)))))
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(define (divides? a b)
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(= (remainder b a) 0))
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(define (time-sd n)
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(define start-time (runtime))
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(smallest-divisor n)
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(- (runtime) start-time))
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; comparing (time-sd 100069) with the new and old versions
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; it's roughly a 1.5 factor increase, likely because the if
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; statement checking is slightly more expensive than simply increasing
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; by one
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