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Sorting algorithms/Heapsort: Difference between revisions
→{{header|Racket}}
(→{{header|Fortran}}: (fix overflow) Fortran allows for, but does not guarantee, short-circuit evaluation of logical operators.) |
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Line 1,979:
>>> heapsort(ary)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]</pre>
=={{header|Racket}}==
<lang racket>
#lang racket
(require (only-in srfi/43 vector-swap!))
(define (heap-sort! xs)
(define (ref i) (vector-ref xs i))
(define (swap! i j) (vector-swap! xs i j))
(define size (vector-length xs))
(define (sift-down! r end)
(define c (+ (* 2 r) 1))
(define c+1 (+ c 1))
(when (<= c end)
(define child
(if (and (<= c+1 end) (< (ref c) (ref c+1)))
c+1 c))
(when (< (ref r) (ref child))
(swap! r child))
(sift-down! child end)))
(for ([i (in-range (quotient (- size 2) 2) -1 -1)])
(sift-down! i (- size 1)))
(for ([end (in-range (- size 1) 0 -1)])
(swap! 0 end)
(sift-down! 0 (- end 1)))
xs)
</lang>
=={{header|REXX}}==
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