sicp-solutions/exercises/ch2/2.3.4/2.70.rkt at master · huanguolin/sicp-solutions · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
#lang scheme

(require "generate-huffman-tree.rkt"
	 "encode.rkt"
	 "decode.rkt")

(define the-tree (generate-huffman-tree
		   '((WAH 1)
		     (BOOM 1)
		     (A 2)
		     (GET 2)
		     (JOB 2)
		     (SHA 3)
		     (YIP 9)
		     (NA 16))))
(define msg '(GET A JOB
              SHA NA NA NA NA NA NA NA NA
	      GET A JOB
	      SHA NA NA NA NA NA NA NA NA
	      WAH YIP YIP YIP YIP YIP YIP YIP YIP YIP
	      SHA BOOM))
(define encode-msg (encode msg the-tree))

(display "message: ")
(newline)
(decode encode-msg the-tree)
(display "encode result: ")
(display encode-msg)
(newline)

(display "encode message length: ")
(length encode-msg)
(display "use fixed-length code, need length: ")
(display (* 3 (length msg)))