The function adjacent_find is used to search for two adjacent elements that are equal or equal according to the predicate argument.
template<class ForwardIterator> ForwardIterator adjacent_find (ForwardIterator first, ForwardIterator last); template<class ForwardIterator, class BinaryPredicate> ForwardIterator adjacent_find (ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
Returns the iterator to the first occurrence found or to last if no occurrence is found.