[SOLVED] CMSI 185 Computer Programming

CMSI 185 Computer Programming
Spring 2017

Homework #4

Part 1

#|

Below is some Racket code.The numbers in the left margin are line numbers.Submit
your hardcopy answers to the questions 1, 2a, 2b, 3a, 3b, 4a, and 4b.

QUESTIONS

1.For each line below, state the line number and describe what that
line does.

2a. What is the purpose of the function lookup?
2b. How does the function lookup work?

3a. What is the purpose of the function translate?
3b. How does the function translate work?

4a. What is the purpose of the function translate_sentence?
4b. How does the function translate_sentence? work?

|#

1#lang racket

2(requireracket/trace)

3(define( translate_sentencesentence )

4 ( displayln sentence )

5 ( if [null? sentence]
;then
6 empty
;else
7 (cons ( translate ( firstsentence) )
8 ( translate_sentence( restsentence) )
)
))

9(define( translateword )

10 (lookup word ((window fenetre) (book livre) (computer ordinateur)
11(house maison) (closed ferme) (pate pate) (liver foie)
12(faith foi) (weekend (fin de semaine))
13((practical joke) attrape) (pal copai)
14(I Je) (love amore)

)
))

15(define( lookupworddictionary )

16 (cond([null? dictionary] (cons word (unknown word) ))

17([equal? word (first (first dictionary))] (first(rest(first dictionary))))

18(else (lookup word(rest dictionary)))
))

;;;TURN ON TRACING
;(trace translate_sentence)

;;;TEST CASES
19(translate computer)

20(translate (practical joke))

21(displayln (translate_sentence
22(I love Racket faith window liver pate house weekend)))

Part 2

A rational number as youve learned in high school actually has two components. The numbers1/2,
3/4, 2/243, and 323/478 are all rational numbers.

A rational number that can be made by dividing two integers, a/b, where a and b are integers and b is
not zero.Sometimes when a