You must write each of the following scheme functions. You must use only basic scheme functions...

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You must write each of the following scheme functions. You must use only basic scheme functions...

You must write each of the following scheme functions. You must use only basic scheme functions (those described in class), do not use third-party libraries to support any of your work. Do not use any function with side effects.

This problem need to use DrRacket software. Racket Language.

Write a function named (key-store L1 KEY) that accepts a list of two-tuples L1 and a value KEY. This function returns the second value of the first tuple that begins with KEY. If L1 doesn't contain the KEY, return the empty list.

(key-store '((a 2) (b c) (c (3 4))) 'c) ---> (3 4)
(key-store '((a 2) (b c) (c (3 4))) 'b) ---> c
(key-store '((a 2) (b c) (c (3 4))) 'z) ---> ()
(key-store '((() a)) '()) ---> a

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Answer 1

Answer #1

CODE:

(define (key-store L1 KEY)
(cond ((null? L1) '()) ;;If List is empty returns NULL list
((equal? (caar L1) KEY) (cadar L1)) ;;If 1st tuple of 1st element of list is equal to key then return 2nd tuple of that element

(else (key-store (cdr L1) KEY)))) ;;else continue searching in rest of list

Snapshot of Code and Output:

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Answer 2

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You must write each of the following scheme functions. You must use only basic scheme functions...

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