set_symmetric_difference(3C++) - set_symmetric_difference(3C++)
Standard C++ Library Copyright 1998, Rogue Wave Software, Inc.
NAMEset_symmetric_difference
- A basic set operation for constructing a sorted symmetric differ‐
ence.
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);
DESCRIPTIONset_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 com‐
parison 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 sec‐
ond.
COMPLEXITY
At most ((last1 - first1) + (last2 - first2)) * 2 -1 comparisons are
performed.
EXAMPLE
//
// set_s_di.cpp
//
#include<algorithm>
#include<set>
#include <istream.h>
using namespace std;
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+0,a1+6), result,
small(a3+0,a3+4);
//Create an insert_iterator for result
insert_iterator<;set<int, less<int> > >
res_ins(result, result.begin());
//Demonstrate set_symmetric_differencecout <;< "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;
}
Program OutputThe symmetric difference of:
{3 5 7 8 } with {1 3 5 7 9 11 } =
{1 8 9 11 }
WARNINGS
If your compiler does not support default template parameters, then you
always need to supply the Compare template argument and the Allocator
template argument. For instance, you need to write:
set<int, less<int>, allocator<int> >
instead of:
set<int>
If your compiler does not support namespaces, then you do not need the
using declaration for std.
SEE ALSO
includes, set, set_union, set_intersection, set_difference
Rogue Wave Software 02 Apr 1998 set_symmetric_difference(3C++)
