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.\" @(#)qsort.3 6.7 (Berkeley) 6/29/91
.Fn qsort "void *base" "size_t nmemb" "size_t size" "int (*compar)(const void *, const void *)"
.Fn heapsort "void *base" "size_t nmemb" "size_t size" "int (*compar)(const void *, const void *)"
function is a modified partition-exchange sort, or quicksort.
function is a modified selection sort.
functions sort an array of
objects, the initial member of which is pointed to by
The size of each object is specified by
The contents of the array are sorted in ascending order according to
a comparison function pointed to by
which is called with two arguments that point to the objects being
The comparison function must return an integer less than, equal to, or
greater than zero if the first argument is considered to be respectively
less than, equal to, or greater than the second.
stable, that is, if two members compare as equal, their order in
the sorted array is undefined.
function is an implementation of C.A.R. Hoare's ``quicksort'' algorithm,
a variant of partition-exchange sorting; in particular, see D.E. Knuth's
takes O N lg N average time.
This implementation uses median selection to avoid the traditional
O N**2 worst-case behavior.
function is an implementation of J.W.J. William's ``heapsort'' algorithm,
a variant of selection sorting; in particular, see D.E. Knuth's Algorithm H.
takes O N lg N worst-case time.
is that it uses no additional memory.
Upon successful completion,
Otherwise, it returns \-1 and the global variable
is set to indicate the error.
function succeeds unless:
did not permit the comparison routine to itself call
.%J "The Computer Journal"
.%J "Communications of the ACM"
.%B "The Art of Computer Programming"
.%T "Sorting and Searching"