thrust::binary_search

Defined in thrust/binary_search.h

template<typename DerivedPolicy, typename ForwardIterator, typename InputIterator, typename OutputIterator, typename StrictWeakOrdering>
OutputIterator thrust::binary_search(const thrust::detail::execution_policy_base<DerivedPolicy> &exec, ForwardIterator first, ForwardIterator last, InputIterator values_first, InputIterator values_last, OutputIterator result, StrictWeakOrdering comp)

binary_search is a vectorized version of binary search: for each iterator v in [values_first, values_last) it attempts to find the value *v in an ordered range [first, last). It returns true if an element that is equivalent to value is present in [first, last) and false if no such element exists. This version of binary_search uses function object comp for comparison.

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

The following code snippet demonstrates how to use binary_search to search for multiple 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;

thrust::device_vector<int> values(6);
values[0] = 0;
values[1] = 1;
values[2] = 2;
values[3] = 3;
values[4] = 8;
values[5] = 9;

thrust::device_vector<bool> output(6);

thrust::binary_search(thrust::device,
                      input.begin(), input.end(),
                      values.begin(), values.end(),
                      output.begin(),
                      thrust::less<T>());

// output is now [true, false, true, false, true, false]

See also

https://en.cppreference.com/w/cpp/algorithm/binary_search

See also

lower_bound

See also

upper_bound

See also

equal_range

Parameters

• exec – The execution policy to use for parallelization.

• first – The beginning of the ordered sequence.

• last – The end of the ordered sequence.

• values_first – The beginning of the search values sequence.

• values_last – The end of the search values sequence.

• result – The beginning of the output sequence.

• comp – The comparison operator.

Template Parameters

• DerivedPolicy – The name of the derived execution policy.

• ForwardIterator – is a model of Forward Iterator.

• InputIterator – is a model of Input Iterator. and InputIterator's value_type is LessThanComparable.

• OutputIterator – is a model of Output Iterator. and bool is convertible to OutputIterator's value_type.

• StrictWeakOrdering – is a model of Strict Weak Ordering.

Pre

The ranges [first,last) and [result, result + (last - first)) shall not overlap.