thrust::unique_count

Defined in thrust/unique.h

template<typename DerivedPolicy, typename ForwardIterator> thrust::iterator_traits<ForwardIterator>::difference_type thrust::unique_count(const thrust::detail::execution_policy_base<DerivedPolicy> &exec, ForwardIterator first, ForwardIterator last)

unique_count counts runs of equal elements in the range [first, last) with the same value,

This version of unique_count uses operator== to test for equality.

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

The following code snippet demonstrates how to use unique_count to determine the number of runs of equal elements using the thrust::host execution policy for parallelization:

#include <thrust/unique.h>
#include <thrust/execution_policy.h>
...
const int N = 7;
int A[N] = {1, 3, 3, 3, 2, 2, 1};
int count = thrust::unique_count(thrust::host, A, A + N);
// count is now 4