Chapter 2, Building Abstractions with Data
Section - 2.3 Symbolic Data
Exercise 2.59
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#lang sicp
(#%require (only racket/base error))
(define (union-set set1 set2)
(cond ((null? set1) set2)
((null? set2) set1)
((element-of-set? (car set1) set2) (union-set (cdr set1) set2))
(else (cons (car set1) (union-set (cdr set1) set2)))
)
)
(define (element-of-set? x set)
(cond ((null? set) false)
((equal? x (car set)) true)
(else (element-of-set? x (cdr set)))
)
)
Test/Output:
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> (display (union-set (list 1 0 5 2 9) (list 10 1 19 5 50)))
(0 2 9 10 1 19 5 50)
>