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+Racket
(Added Dyalect programming language) |
(+Racket) |
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Line 823:
[(4, 3), (2, 1), (-1, -2), (3.9, 10)] -> [(-2, -1), (1, 2), (3, 10)]
[(1, 3), (-6, -1), (-4, -5), (8, 2), (-6, -6)] -> [(-6, -1), (1, 8)]</pre>
=={{header|Racket}}==
<lang racket>#lang racket
;; Racket's max and min allow inexact numbers to contaminate exact numbers
;; Use argmax and argmin instead, as they don't have this problem
(define (max . xs) (argmax identity xs))
(define (min . xs) (argmin identity xs))
;; a bag is a list of disjoint intervals
(define ((irrelevant? x y) item) (or (< (second item) x) (> (first item) y)))
(define (insert bag x y)
(define-values (irrelevant relevant) (partition (irrelevant? x y) bag))
(cons (list (apply min x (map first relevant))
(apply max y (map second relevant))) irrelevant))
(define (solve xs)
(sort (for/fold ([bag '()]) ([x (in-list xs)])
(insert bag (apply min x) (apply max x))) < #:key first))
(define inputs '(([1.1 2.2])
([6.1 7.2] [7.2 8.3])
([4 3] [2 1])
([4 3] [2 1] [-1 -2] [3.9 10])
([1 3] [-6 -1] [-4 -5] [8 2] [-6 -6])))
(for ([xs (in-list inputs)]) (printf "~a => ~a\n" xs (solve xs)))</lang>
{{out}}
<pre>
((1.1 2.2)) => ((1.1 2.2))
((6.1 7.2) (7.2 8.3)) => ((6.1 8.3))
((4 3) (2 1)) => ((1 2) (3 4))
((4 3) (2 1) (-1 -2) (3.9 10)) => ((-2 -1) (1 2) (3 10))
((1 3) (-6 -1) (-4 -5) (8 2) (-6 -6)) => ((-6 -1) (1 8))
</pre>
=={{header|REXX}}==
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