Other
PROBLEM SET
- Course
- Institution
IT IS A PROBLEM SET
[Show more]
Seller
Followaryanjain5
Content preview
;; DO NOT PUT ANYTHING PERSONALLY IDENTIFYING BEYOND YOUR CWL IN THIS FILE.;; YOUR CWLs WILL BE SUFFICIENT TO IDENTIFY YOU AND, IF YOU HAVE ONE, YOUR
;; PARTNER.
;;
(require spd/tags)
(@assignment psets/pset-07); Do not edit or remove this tag
;; If you are:
;; - A 110 or 107 student replace the rst set of '???'s with your cwl.
;; For problem sets, If you have a partner, please replace the second
;; set of '???'s with their cwl. Remember this, it is what you will
;; do with these @cwl annotations for the whole course.
;; - A UBC Extended Learning student, replace the rst set of ??? with
;; your email address as con rmed in the email you received from
;; extended learning. The handin password is also in that email.
;; Remember this, it is what you will do with these @cwl annotations
;; for the whole course.
;;
(@cwl ??? ???)
(@problem 1)
;; There is a primitive type called 1String, de ned as follows:
;;
;; 1String is String
;; interp. a 1String represents a single letter
;; CONSTRAINT: any 1String is only one letter long
(@htdd ListOf1String)
;; ListOf1String is one of:
;; - empty
;; - (cons 1String ListOf1String)
;; interp. a sequence of letters
(de ne L1 empty)
(de ne L2 (list "a" "B" "c"))
(@htdd Operations)
;; Operations is one of:
;; - empty
;; - (cons "keep" Operations)
;; - (cons "space" Operations)
;; - (cons "remove" Operations)
;; interp. a sequence of operations to apply to a list of 1String
;; "keep" means keep the corresponding letter
;; "space" means replace the corresponding letter with a " "
;; "remove" means remove the corresponding letter
;;
;; In this problem you will design a function called decoder, that will
;; decode encrypted messages! Very poorly encrypted messages. The function
;; consumes a ListOf1String (l) and Operations (ops) in that order. The
;; function should produce a String which is the result of applying the
fi fi fi fi fi
, ;; given operations to the successive 1String and joining the resulting
;; letters together.
;;
;; For example:
;; (decoder (list "i" "k" "l" "h" "a" "m" "k" "s" "a" "r" "m")
;; (list "keep" "remove" "remove" "space" "keep" "keep"
;; "space" "keep" "keep" "remove"))
;;
;; should produce "i am sam"
;;
;; Notice that some of the letters were kept, some were replaced with a space,
;; and some were removed.
;;
;; If ops runs out of operations before the end of the 1String, then all
;; the remaining letters in l are kept.
;;
;; If l runs out of 1String rst, then the remaining operations in ops are
;; ignored.
;;
;; Example 2:
;; (decoder (list "f" "a" "d" "e")
;; (list "remove" "keep" "space" "keep" "remove" "keep" "space"))
;;
;; should produce "a e"
;;
;; You MUST SOLVE THIS AS A 2-ONE-OF PROBLEM and your solution must include
;; a table. You must use numbers to show the correspondence between table cells
;; and cond QA pairs. By this, we mean you should NUMBER the table cells and
;; NUMBER the corresponding cond QA pairs with the same numbers (as was done
;; in lecture). If you can simplify the table you should. Finally, it is
;; IMPERATIVE that your cond questions only include the kinds of questions that
;; the data driven template rules produce, other conditional behaviour must go
;; into the cond answers. (This is the rule about not editing template questions
;; carried over into 2-one-of problems.)
;;
(@htdf decoder) ;!!! uncomment this when you start your function design
(@signature ListOf1String Operations -> String)
;; produce a string result of applying the oper. to the strings and append them
(check-expect (decoder empty empty) "")
(check-expect (decoder (list "a") empty) "a")
(check-expect (decoder empty (list "keep")) "")
(check-expect (decoder empty (list "space")) "")
(check-expect (decoder empty (list "remove")) "")
(check-expect (decoder (list "a") (list "keep")) "a")
(check-expect (decoder (list "a") (list "remove")) "")
(check-expect (decoder (list "a") (list "space")) " ")
(check-expect (decoder (list "f" "a" "d" "e")
(list "remove" "keep" "space" "keep"
"remove" "keep" "space"))
"a e")
(check-expect (decoder (list "i" "k" "l" "h" "a" "m" "k" "s" "a" "r" "m")
fi
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller aryanjain5. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $7.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
72042 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now