adjacent_find

Interface

template<typename ForwardIterator, typename BinaryPredicate>
inline SPROUT_CONSTEXPR ForwardIterator
adjacent_find(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);

template<typename ForwardIterator>
inline SPROUT_CONSTEXPR ForwardIterator
adjacent_find(ForwardIterator first, ForwardIterator last);

Returns

The first iterator i such that both i and i + 1 are in the range [first,last) for which the following corresponding conditions hold: *i == *(i + 1), pred(*i, *(i + 1)).

Returns last if no such iterator is found.

Examples

#include <sprout/algorithm/adjacent_find.hpp>
#include <sprout/array.hpp>
#include <sprout/container.hpp>
using namespace sprout;

SPROUT_STATIC_CONSTEXPR auto input = array<int, 10>{{1, 2, 3, 5, 5, 6, 6, 8, 9, 10}};
SPROUT_STATIC_CONSTEXPR auto result = sprout::adjacent_find(begin(input), end(input));
static_assert(result != end(input), "found adjacent elements equal to each other from input.");
static_assert(result - begin(input) == 3, "a found position is 3.");

Complexity

For a nonempty range, exactly min((i - first) + 1, (last - first) - 1) applications of the corresponding predicate, where i is adjacent_find’s return value.

Recursive function invocations in O(logN) (logarithmic) depth.

Header

sprout/algorithm/adjacent_find.hpp

Convenience header: sprout/algorithm.hpp