XmacsLabs/planet
1
0
Fork 0
mirror of https://gitee.com/XmacsLabs/planet.git synced 2025-09-06 14:43:52 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

SICP 05: 代码清单

Browse source
This commit is contained in:
Darcy Shen 2024-03-13 22:01:27 +08:00
parent d88c911ec0
commit b9db91859c
2 changed files with 134 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

131
SICP/code05.tm Normal file
View file

@ -0,0 +1,131 @@
<TeXmacs|2.1.2>
<style|<tuple|generic|no-page-numbers|british|reduced-margins>>
<\body>
<section*|Orders of Growth>
<\session|scheme|default>
<\unfolded-io|Scheme] >
(define (expt-1 b n)
\ \ (if (= n 0)
\ \ \ \ \ \ 1
\ \ \ \ \ \ (* b (expt-1 b (- n 1)))))
<|unfolded-io>
expt-1
</unfolded-io>
<\unfolded-io|Scheme] >
(expt-1 1 0)
<|unfolded-io>
1
</unfolded-io>
<\unfolded-io|Scheme] >
(expt-1 2 3)
<|unfolded-io>
8
</unfolded-io>
<\unfolded-io|Scheme] >
(define (expt-2 b n)
\ \ (define (expt-iter b counter product)
\ \ \ \ (if (= counter 0)
\ \ \ \ \ \ \ \ product
\ \ \ \ \ \ \ \ (expt-iter b
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (- counter 1)
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (* b product))))
\ \
\ \ (expt-iter b n 1))
<|unfolded-io>
expt-2
</unfolded-io>
<\unfolded-io|Scheme] >
(expt-2 3 3)
<|unfolded-io>
27
</unfolded-io>
<\input|Scheme] >
\;
</input>
</session>
<section*|Exponentiation>
<\session|scheme|default>
<\unfolded-io|Scheme] >
(define (fast-expt b n)
\ \ (define (even? n)
\ \ \ \ (= (remainder n 2) 0))
\ \ (define (square x) (* x x))
\ \
\ \ (cond ((= n 0) 1)
\ \ \ \ \ \ \ \ ((even? n) (square (fast-expt b (/ n 2))))
\ \ \ \ \ \ \ \ (else (* b (fast-expt b (- n 1))))))
<|unfolded-io>
fast-expt
</unfolded-io>
<\unfolded-io|Scheme] >
(fast-expt 3 3)
<|unfolded-io>
27
</unfolded-io>
</session>
<section*|Greatest Common Divisors>
<\session|scheme|default>
<\unfolded-io|Scheme] >
(define (gcd a b)
\ \ (if (= b 0)
\ \ \ \ \ \ a
\ \ \ \ \ \ (gcd b (remainder a b))))
<|unfolded-io>
gcd
</unfolded-io>
<\unfolded-io|Scheme] >
(gcd 10 20)
<|unfolded-io>
10
</unfolded-io>
</session>
</body>
<\initial>
<\collection>
<associate|page-screen-margin|true>
</collection>
</initial>
<\references>
<\collection>
<associate|auto-1|<tuple|?|?>>
<associate|auto-2|<tuple|?|?>>
<associate|auto-3|<tuple|?|?>>
</collection>
</references>