Template Function thrust::set_symmetric_difference(InputIterator1, InputIterator1, InputIterator2, InputIterator2, OutputIterator, StrictWeakCompare)

Function Documentation

template<typename InputIterator1, typename InputIterator2, typename OutputIterator, typename StrictWeakCompare>
OutputIterator thrust::set_symmetric_difference(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result, StrictWeakCompare comp)

set_symmetric_difference constructs a sorted range that is the set symmetric difference of the sorted ranges [first1, last1) and [first2, last2). The return value is the end of the output range.

In the simplest case, set_symmetric_difference performs a set theoretic calculation: it constructs the union of the two sets A - B and B - A, where A and B are the two input ranges. That is, the output range contains a copy of every element that is contained in [first1, last1) but not [first2, last1), and a copy of every element that is contained in [first2, last2) but not [first1, last1). The general case is more complicated, because the input ranges may contain duplicate elements. The generalization is that if [first1, last1) contains m elements that are equivalent to each other and [first2, last1) contains n elements that are equivalent to them, then |m - n| of those elements shall be copied to the output range: the last m - n elements from [first1, last1) if m > n, and the last n - m of these elements from [first2, last2) if m < n.

This version of set_union compares elements using a function object comp.

The following code snippet demonstrates how to use

set_symmetric_difference to compute the symmetric difference of two sets of integers sorted in descending order.
Return

The end of the output range.

Pre

The ranges [first1, last1) and [first2, last2) shall be sorted with respect to comp.

Pre

The resulting range shall not overlap with either input range.

Parameters

  • first1: The beginning of the first input range.

  • last1: The end of the first input range.

  • first2: The beginning of the second input range.

  • last2: The end of the second input range.

  • result: The beginning of the output range.

  • comp: Comparison operator.

Template Parameters

  • InputIterator1: is a model of Input Iterator, InputIterator1 and InputIterator2 have the same value_type, InputIterator1's value_type is a model of LessThan Comparable, the ordering on InputIterator1's value_type is a strict weak ordering, as defined in the LessThan Comparable requirements, and InputIterator1's value_type is convertable to a type in OutputIterator's set of value_types.

  • InputIterator2: is a model of Input Iterator, InputIterator2 and InputIterator1 have the same value_type, InputIterator2's value_type is a model of LessThan Comparable, the ordering on InputIterator2's value_type is a strict weak ordering, as defined in the LessThan Comparable requirements, and InputIterator2's value_type is convertable to a type in OutputIterator's set of value_types.

  • OutputIterator: is a model of Output Iterator.

#include <thrust/set_operations.h>
...
int A1[6] = {7, 6, 4, 2, 2, 1, 0};
int A2[5] = {8, 5, 2, 1, 1};

int result[6];

int *result_end = thrust::set_symmetric_difference(A1, A1 + 6, A2, A2 + 5, result);
// result = {8, 7, 6, 5, 4, 0}

See

http://www.sgi.com/tech/stl/set_symmetric_difference.html

See

merge

See

includes

See

set_difference

See

set_union

See

set_intersection

See

sort

See

is_sorted