15 lines
449 B
Scheme
15 lines
449 B
Scheme
#lang sicp
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(define (element-of-set? x set)
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(cond ((null? set) false)
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((equal? x (car set)) true)
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(else (element-of-set? x (cdr set)))))
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; we will simply adjoin elements of set1 to set2 if they are not there
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; and drop them if they are there
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(define (union-set set1 set2)
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(cond ((null? set1) set2)
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((null? set2) set1)
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((element-of-set? (car set1) set2)
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(union-set (cdr set1) set2))
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(else (union-set (cdr set1) (cons (car set1) set2)))))
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