23 lines
420 B
Scheme
23 lines
420 B
Scheme
#lang sicp
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(define (make-interval a b) (cons a b))
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(define (lower-bound i)
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(car i))
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(define (upper-bound i)
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(cdr i))
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(define (make-center-percent c p)
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(make-interval (- c (* c p 1/100))
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(+ c (* c p 1/100))))
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(define (center i)
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(/ (+ (lower-bound i) (upper-bound i)) 2))
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(define (width i)
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(/ (- (upper-bound i) (lower-bound i)) 2))
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(define (percent i)
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(* (/ (width i) (center i)) 100))
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