SICP 05: 代码清单

SICP/code05.tm

@@ -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>

SICP/index.tm

@@ -24,13 +24,13 @@
       <item>\<#76EE\>\<#6807\>\<#90AE\>\<#7BB1\>\<#FF1A\>shenda AT ustc.edu
     </itemize>
 
-    <item>\<#7B2C\>5\<#8BFE\>\<#FF1A\>\<#7B97\>\<#6CD5\>\<#7684\>\<#65F6\>\<#95F4\>\<#590D\>\<#6742\>\<#5EA6\>
+    <item>\<#7B2C\>5\<#8BFE\>\<#FF1A\>\<#7B97\>\<#6CD5\>\<#7684\>\<#65F6\>\<#7A7A\>\<#590D\>\<#6742\>\<#5EA6\>
 
-    \<#8BB2\>\<#4E49\>\<#FF1A\>\<#4EA4\>\<#4E92\>\<#5F0F\>\<#8BB2\>\<#4E49\>05
+    \<#8BB2\>\<#4E49\>\<#FF1A\><hlink|\<#4EA4\>\<#4E92\>\<#5F0F\>\<#8BB2\>\<#4E49\>05|https://gitee.com/XmacsLabs/interactive-sicp/raw/main/course05.tm>
 
     \<#8BFE\>\<#4EF6\>\<#FF1A\>\<#5E7B\>\<#706F\>\<#7247\>05
 
-    \<#4EE3\>\<#7801\>\<#FF1A\>\<#4EE3\>\<#7801\>\<#6E05\>\<#5355\>05
+    \<#4EE3\>\<#7801\>\<#FF1A\><hlink|\<#4EE3\>\<#7801\>\<#6E05\>\<#5355\>05|code05.tm>
 
     <item>\<#7B2C\>4\<#8BFE\>\<#FF1A\>\<#9012\>\<#5F52\>\<#4E0E\>\<#8FED\>\<#4EE3\>\<#FF08\>\<#4E60\>\<#9898\>\<#8BFE\>\<#FF09\>