#lang racket
(provide hours
kg2lb
timezone)
; Please do not modify the lines above this one.
; ********************************************************
; CS 201 HW #0 DUE Wednesday 9/10/2025, 11:59 pm
; ** submit online using gradescope.
; ********************************************************
; Name:
; Email address:
; ********************************************************
; This file may be loaded into Racket. Lines beginning with
; semicolons are comments.
; Homework #0 will be worth 20 points -- other homeworks will be worth
; 100 points (or so).
; You will be submitting *two* files for homework #0. Please name
; them: hw0.rkt (for the Racket definitions and procedures)
; response.pdf (for the reading response)
; ********************************************************
; ** problem 0 ** (1 easy point)
; Replace the number 0 in the definition below to indicate how many
; hours you spent doing this assignment. Fractions are fine, eg,
; 3.14159. You will receive no credit for this problem if you leave
; the number as 0.
(define hours 0)
; ********************************************************
; ** problem 1 ** (5 points)
; Write a procedure (kg2lb mass)
; which converts a mass in kilograms to the equivalent mass in pounds
; and ounces. There are 2.2 pounds per kilogram. There are 16 ounces
; in a pound. All values are rounded down to the nearest integer.
; Examples
; (kg2lb .5) => '(1 pound 1 ounce)
; (kg2lb 1) => '(2 pounds 3 ounces)
; (kg2lb 2) => '(4 pounds 6 ounces)
; (kg2lb 3) => '(6 pounds 9 ounces)
; (kg2lb 4) => '(8 pounds 12 ounces)
; (kg2lb 9) => '(19 pounds 12 ounces)
; (kg2lb 10) => '(22 pounds 0 ounces)
; (kg2lb 100) => '(220 pounds 0 ounces)
; ********************************************************
; Replace "empty" in the code below with your procedure. Make sure it
; is named kg2lb and has one argument. The name of the argument is
; not important.
; Your procedure will be tested automatically with positive arguments.
(define (kg2lb mass)
empty)
; ********************************************************
; ** problem 2 ** (4 points)
; Write a procedure (timezone) that takes no arguments and returns a
; *string* indicating your time zone.
; Please remember the difference between a procedure call and the
; evaluation of a variable!
; Example (yours might be different)
; (timezone) => "EST"
; ********************************************************
; Replace "empty" in the code below with your procedure. Make sure it
; is named timezone and takes no arguments. Your procedure will be
; tested automatically, and will be called only with no arguments.
(define (timezone)
empty)
; ********************************************************
; ** problem 3 ** (10 points)
; For this problem, you are asked to find one article (of 2 pages or
; more) in the magazine "Communications of the ACM", in one of the
; issues: June, July, August, September 2025 See http://cacm.acm.org/
; read the article and answer the following three questions:
; a. What did you know about the topic
; prior to reading the article?
; b. What did you learn from reading the
; article?
; c. What more would you like to know
; about the topic?
; Your answer should be AT MOST 2 pages saved in pdf format, and
; submitted as the file response.pdf for assignment 0. Please include
; in your file your name and email address and the title and author(s)
; of the article you are responding to.
; Your grade for this problem will be 10 if we can open, print and read
; your submitted pdf file. It is to help us get acquainted with you
; and your interests -- you won't receive feedback on your answers.
; ********************************************************
; ******** testing, testing. 1, 2, 3 ....
; ********************************************************
(define *testing-flag* #t)
(define (oldtest name got expected)
(cond (*testing-flag*
(let* ((expected (if (procedure? expected)
(if (expected got) 'OK-TEST
'FAILED-TEST)
expected))
(prefix (if (equal? got expected)
'OK
'X)))
(list 'testing name prefix 'got: got 'expected: expected)))))
(define (test name got expected)
(cond (*testing-flag*
(let* ((OK (if (procedure? expected)
(expected got)
(equal? got expected)))
(prefix (if OK
'OK
'X)))
(list 'testing name prefix 'got: got 'expected: expected)))))
(define (runtests)
(list
(test 'hours hours (lambda (x) (> x 0)))
(test 'kg2lb (kg2lb .5) '(1 pound 1 ounce))
(test 'kg2lb (kg2lb 1) '(2 pounds 3 ounces))
(test 'kg2lb (kg2lb 2) '(4 pounds 6 ounces))
(test 'kg2lb (kg2lb 3) '(6 pounds 9 ounces))
(test 'kg2lb (kg2lb 4) '(8 pounds 12 ounces))
(test 'kg2lb (kg2lb 9) '(19 pounds 12 ounces))
(test 'kg2lb (kg2lb 10) '(22 pounds 0 ounces))
(test 'kg2lb (kg2lb 100) '(220 pounds 0 ounces))
(test 'timezone (timezone) (lambda (x) (string? x)))
)
)
;; Unit tests. See
;; http://docs.racket-lang.org/rackunit/quick-start.html
;; for documentation on Racket's unit testing library.
(require rackunit)
(define kg2lb-tests
(test-suite
"tests for kg2lb procedure"
(check-equal? (kg2lb .5) '(1 pound 1 ounce) "convert .5 kg")
(check-equal? (kg2lb 1) '(2 pounds 3 ounces) "convert 1 kg")
(check-equal? (kg2lb 2) '(4 pounds 6 ounces) "convert 2 kg")
(check-equal? (kg2lb 3) '(6 pounds 9 ounces) "convert 3 kg")
(check-equal? (kg2lb 4) '(8 pounds 12 ounces) "convert 4 kg")
(check-equal? (kg2lb 9) '(19 pounds 12 ounces) "convert 9 kg")
(check-equal? (kg2lb 10) '(22 pounds 0 ounces) "convert 10 kg")
(check-equal? (kg2lb 100) '(220 pounds 0 ounces) "convert 100 kg")
(check-pred positive? hours "hours must be positive")
(check-pred string? (timezone) "(timezone) must return a string")
))
(require rackunit/text-ui)
(define (run-kg2lb-tests [verbosity 'normal])
(run-tests kg2lb-tests verbosity))
; ********************************************************
; ******** end of homework #0
; ********************************************************