set_symmetric_difference (3C++std) - Tru64 UNIX
Standard C++ LibraryCopyright 1996, Rogue Wave Software, Inc.
NAME
set_symmetric_difference - Basic set operation for sorted sequences.
SYNOPSIS
#include <algorithm>
template <class InputIterator1, class InputIterator2,
class OutputIterator>
OutputIterator
set_symmetric_difference (InputIterator1 first1,
InputIterator1 last1,
InputIterator2 first2,
InputIterator2 last2,
OutputIterator result);
template <class InputIterator1, class InputIterator2,
class OutputIterator, class Compare>
OutputIterator
set_symmetric_difference (InputIterator1 first1,
InputIterator1 last1,
InputIterator2 first2,
InputIterator2 last2,
OutputIterator result, Compare comp);
DESCRIPTION
set_symmetric_difference constructs a sorted symmetric difference of the
elements from the two ranges. This means that the constructed range
includes copies of the elements that are present in the range [first1,
last1) but not present in the range [first2, last2)and copies of the
elements that are present in the range [first2, last2) but not in the range
[first1, last1). It returns the end of the constructed range.
For example, suppose we have two sets:
1 2 3 4 5
and
3 4 5 6 7
The set_symmetric_difference of these two sets is:
1 2 6 7
The result of set_symmetric_difference is undefined if the result range
overlaps with either of the original ranges.
set_symmetric_difference assumes that the ranges are sorted using the
default comparison operator less than (<), unless an alternative comparison
operator (comp) is provided.
Use the set_symmetric_difference algorithm to return a result that includes
elements that are present in the first set and not in the second.
COMPLEXITY
At most ((last1 - first1) + (last2 - first2)) * 2 -1 comparisons are
performed.
EXAMPLE
//
// set_s_di.cpp
//
#include<algorithm>
#include<set>
#include <istream.h>
int main()
{
//Initialize some sets
int a1[] = {1,3,5,7,9,11};
int a3[] = {3,5,7,8};
set<int, less<int> > odd(a1,a1+6), result,
small(a3,a3+4);
//Create an insert_iterator for result
insert_iterator<set<int, less<int> > >
res_ins(result, result.begin());
//Demonstrate set_symmetric_difference
cout << "The symmetric difference of:" << endl << "{";
copy(small.begin(),small.end(),
ostream_iterator<int,char>(cout," "));
cout << "} with {";
copy(odd.begin(),odd.end(),
ostream_iterator<int,char>(cout," "));
cout << "} =" << endl << "{";
set_symmetric_difference(small.begin(), small.end(),
odd.begin(), odd.end(), res_ins);
copy(result.begin(),result.end(),
ostream_iterator<int,char>(cout," "));
cout << "}" << endl << endl;
return 0;
}
Output :
The symmetric difference of:
{3 5 7 8 } with {1 3 5 7 9 11 } =
{1 8 9 11 }
WARNING
If your compiler does not support default template parameters, then you
need to always supply the Compare template argument and the Allocator
template argument. For instance, you will need to write :
set<int, less<int>, allocator<int> >
instead of :
set<int>
SEE ALSO
includes, set, set_union, set_intersection, set_difference
STANDARDS CONFORMANCE
ANSI X3J16/ISO WG21 Joint C++ Committee
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