thrust::equal_range #

See also

See also

Parameters:

exec – The execution policy to use for parallelization.
first – The beginning of the ordered sequence.
last – The end of the ordered sequence.
value – The value to be searched.

Template Parameters:

DerivedPolicy – The name of the derived execution policy.
ForwardIterator – is a model of Forward Iterator.
LessThanComparable – is a model of LessThanComparable.

Returns:

A pair of iterators [i, j) that define the range of equivalent elements.

`equal_range(first, last, value)`#

template<class ForwardIterator, class LessThanComparable> thrust::pair<ForwardIterator, ForwardIterator> thrust::equal_range( ForwardIterator first, ForwardIterator last, const LessThanComparable &value, )#

equal_range is a version of binary search: it attempts to find the element value in an ordered range [first, last). The value returned by equal_range is essentially a combination of the values returned by lower_bound and upper_bound: it returns a pair of iterators i and j such that i is the first position where value could be inserted without violating the ordering and j is the last position where value could be inserted without violating the ordering. It follows that every element in the range [i, j) is equivalent to value, and that [i, j) is the largest subrange of [first, last) that has this property.

This version of equal_range returns a pair of iterators [i, j), where i is the furthermost iterator in [first, last) such that, for every iterator k in [first, i), *k < value. j is the furthermost iterator in [first, last) such that, for every iterator k in [first, j), value < *k is false. For every iterator k in [i, j), neither value < *k nor *k < value is true.

The following code snippet demonstrates how to use equal_range to search for values in a ordered range.

#include <thrust/binary_search.h>
#include <thrust/device_vector.h>
...
thrust::device_vector<int> input(5);

input[0] = 0;
input[1] = 2;
input[2] = 5;
input[3] = 7;
input[4] = 8;

thrust::equal_range(input.begin(), input.end(), 0); // returns [input.begin(), input.begin() + 1)
thrust::equal_range(input.begin(), input.end(), 1); // returns [input.begin() + 1, input.begin() + 1)
thrust::equal_range(input.begin(), input.end(), 2); // returns [input.begin() + 1, input.begin() + 2)
thrust::equal_range(input.begin(), input.end(), 3); // returns [input.begin() + 2, input.begin() + 2)
thrust::equal_range(input.begin(), input.end(), 8); // returns [input.begin() + 4, input.end())
thrust::equal_range(input.begin(), input.end(), 9); // returns [input.end(), input.end())

See also

See also

See also

Parameters:

first – The beginning of the ordered sequence.
last – The end of the ordered sequence.
value – The value to be searched.

Template Parameters:

ForwardIterator – is a model of Forward Iterator.
LessThanComparable – is a model of LessThanComparable.

Returns:

A pair of iterators [i, j) that define the range of equivalent elements.

`equal_range(exec, first, last, value, comp)`#

template<typename DerivedPolicy, typename ForwardIterator, typename T, typename StrictWeakOrdering> thrust::pair<ForwardIterator, ForwardIterator> thrust::equal_range( const thrust::detail::execution_policy_base<DerivedPolicy> &exec, ForwardIterator first, ForwardIterator last, const T &value, StrictWeakOrdering comp, )#

equal_range is a version of binary search: it attempts to find the element value in an ordered range [first, last). The value returned by equal_range is essentially a combination of the values returned by lower_bound and upper_bound: it returns a pair of iterators i and j such that i is the first position where value could be inserted without violating the ordering and j is the last position where value could be inserted without violating the ordering. It follows that every element in the range [i, j) is equivalent to value, and that [i, j) is the largest subrange of [first, last) that has this property.

This version of equal_range returns a pair of iterators [i, j). i is the furthermost iterator in [first, last) such that, for every iterator k in [first, i), comp(*k, value) is true. j is the furthermost iterator in [first, last) such that, for every iterator k in [first, last), comp(value, *k) is false. For every iterator k in [i, j), neither comp(value, *k) nor comp(*k, value) is true.

The algorithm’s execution is parallelized as determined by exec.

The following code snippet demonstrates how to use equal_range to search for values in a ordered range using the thrust::device execution policy for parallelization:

#include <thrust/binary_search.h>
#include <thrust/device_vector.h>
#include <thrust/functional.h>
#include <thrust/execution_policy.h>
...
thrust::device_vector<int> input(5);

input[0] = 0;
input[1] = 2;
input[2] = 5;
input[3] = 7;
input[4] = 8;

using ::cuda::std::less;

thrust::equal_range(thrust::device, input.begin(), input.end(), 0, less<int>());
// returns [input.begin(), input.begin() + 1)
thrust::equal_range(thrust::device, input.begin(), input.end(), 1, less<int>());
// returns [input.begin() + 1, input.begin() + 1)
thrust::equal_range(thrust::device, input.begin(), input.end(), 2, less<int>());
// returns [input.begin() + 1, input.begin() + 2)
thrust::equal_range(thrust::device, input.begin(), input.end(), 3, less<int>());
// returns [input.begin() + 2, input.begin() + 2)
thrust::equal_range(thrust::device, input.begin(), input.end(), 8, less<int>());
// returns [input.begin() + 4, input.end())
thrust::equal_range(thrust::device, input.begin(), input.end(), 9, less<int>());
// returns [input.end(), input.end())

See also

See also

See also

Parameters:

exec – The execution policy to use for parallelization.
first – The beginning of the ordered sequence.
last – The end of the ordered sequence.
value – The value to be searched.
comp – The comparison operator.

Template Parameters:

DerivedPolicy – The name of the derived execution policy.
ForwardIterator – is a model of Forward Iterator.
T – is comparable to ForwardIterator's value_type.
StrictWeakOrdering – is a model of Strict Weak Ordering.

Returns:

A pair of iterators [i, j) that define the range of equivalent elements.

`equal_range(first, last, value, comp)`#

template<class ForwardIterator, class T, class StrictWeakOrdering> thrust::pair<ForwardIterator, ForwardIterator> thrust::equal_range( ForwardIterator first, ForwardIterator last, const T &value, StrictWeakOrdering comp, )#

equal_range is a version of binary search: it attempts to find the element value in an ordered range [first, last). The value returned by equal_range is essentially a combination of the values returned by lower_bound and upper_bound: it returns a pair of iterators i and j such that i is the first position where value could be inserted without violating the ordering and j is the last position where value could be inserted without violating the ordering. It follows that every element in the range [i, j) is equivalent to value, and that [i, j) is the largest subrange of [first, last) that has this property.

This version of equal_range returns a pair of iterators [i, j). i is the furthermost iterator in [first, last) such that, for every iterator k in [first, i), comp(*k, value) is true. j is the furthermost iterator in [first, last) such that, for every iterator k in [first, last), comp(value, *k) is false. For every iterator k in [i, j), neither comp(value, *k) nor comp(*k, value) is true.

The following code snippet demonstrates how to use equal_range to search for values in a ordered range.

#include <thrust/binary_search.h>
#include <thrust/device_vector.h>
#include <thrust/functional.h>
...
thrust::device_vector<int> input(5);

input[0] = 0;
input[1] = 2;
input[2] = 5;
input[3] = 7;
input[4] = 8;

using ::cuda::std::less;

thrust::equal_range(input.begin(), input.end(), 0, less<int>());
// returns [input.begin(), input.begin() + 1)
thrust::equal_range(input.begin(), input.end(), 1, less<int>());
// returns [input.begin() + 1, input.begin() + 1)
thrust::equal_range(input.begin(), input.end(), 2, less<int>());
// returns [input.begin() * + 1, input.begin() + 2)
thrust::equal_range(input.begin(), input.end(), 3, less<int>());
// returns [input.begin() + 2, input.begin() + 2)
thrust::equal_range(input.begin(), input.end(), 8, less<int>());
// returns [input.begin() + 4, input.end())
thrust::equal_range(input.begin(), input.end(), 9, less<int>());
// returns [input.end(), input.end())

See also

See also

See also