.\" ident	@(#)Array_alg:man/set_remove.3	3.2
.\"
.\" C++ Standard Components, Release 3.0.
.\"
.\" Copyright (c) 1991, 1992 AT&T and UNIX System Laboratories, Inc.
.\" Copyright (c) 1988, 1989, 1990 AT&T.  All Rights Reserved.
.\"
.\" THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T and UNIX System
.\" Laboratories, Inc.  The copyright notice above does not evidence
.\" any actual or intended publication of such source code.
.\" 
.TH \f3set_remove\fP \f3Array_alg(3C++)\fP " "
.SH NAME
set_remove \- treating arrays as sets, remove an element
.SH SYNOPSIS OF Array_alg.h
.Bf

    template <class \*(gt>
    \*(gt* set_remove(
	const \*(gt& val, 
	\*(gt* b, 
	\*(gt* e
    );
    template <class \*(gt>
    \*(gt* set_remove_r(
        int (*rel)(const \*(gt*,const \*(gt*),
	const \*(gt& val, 
	\*(gt* b, 
	\*(gt* e
    );
.Be
.SH ASSUMPTIONS
.PP
.br
(1) For the plain version, \f4\*(gt::operator<\f1
defines a total ordering relation on \*(gt and the 
array is sorted w.r.t. that relation.
.br
(2) For the relational version, \f4rel\f1 defines 
a total ordering relation on \*(gt and the array is
sorted w.r.t. that relation.
.br
(3) The input array does not contain any repetitions.
.br
(4) \*(gt has \f4operator=\f1
.SH DESCRIPTION
.PP
If a sorted array with no repetitions contains an element 
equal to \f4val\f1, these functions remove it in such a 
way that the array remains sorted.  
They return a pointer to the cell just beyond the cell 
containing the last remaining element.
.sp 0.5v
.IP "\f4template <class \*(gt>\f1"
.IC "\f4\*(gt* set_remove(\f1"
.IC "\f4    const \*(gt& val,\f1" 
.IC "\f4    \*(gt* b,\f1" 
.IC "\f4    \*(gt* e\f1"
.IC "\f4);\f1"
Uses \f4\*(gt::operator<\f1 to find the element.
.IP "\f4template <class \*(gt>\f1"
.IC "\f4\*(gt* set_remove_r(\f1"
.IC "\f4    int (*rel)(const \*(gt*,const \*(gt*),\f1"
.IC "\f4    const \*(gt& val,\f1" 
.IC "\f4    \*(gt* b,\f1" 
.IC "\f4    \*(gt* e\f1"
.IC "\f4);\f1"
Uses \f4rel\f1 to find the element.
.SH COMPLEXITY
.PP
If \f2N\f1 is the size of the array,
then complexity is \f2O(N)\f1.
At most \f2N\f1 assignments and at most \f2lgN\f1 tests of
the ordering relation are done.
.SH NOTES
All functions whose names begin with \f3set_\f1
treat arrays as sets (they share assumptions 1\-3).
These all have linear time complexity, which may 
unacceptable for large sets.
As an alternative, consider using \f3Set(3C++)\f1 
or \f3Bits(3C++)\f1
(if \*(gt is \f4int\f1).
.PP
Because a Block (see \f3Block(3C++)\f1)
can always be used wherever an array is called for,
Array Algorithms can also be used with Blocks.
In fact, these two components were actually designed 
to be used together.
.SH SEE ALSO
.Bf

\f3intro(.)\f1
\f3insert(.)\f1
\f3set_diff(.)\f1
\f3set_inter(.)\f1
\f3set_union(.)\f1
\f3set_sdiff(.)\f1

\f3Bits(3C++)\f1
\f3Block(3C++)\f1
\f3Set(3C++)\f1
.Be