find_end

Interface

template<typename ForwardIterator1, typename ForwardIterator2>
inline SPROUT_CONSTEXPR ForwardIterator1
find_end(
  ForwardIterator1 first1, ForwardIterator1 last1,
  ForwardIterator2 first2, ForwardIterator2 last2
  );

template<typename ForwardIterator1, typename ForwardIterator2, typename BinaryPredicate>
inline SPROUT_CONSTEXPR ForwardIterator1
find_end(
  ForwardIterator1 first1, ForwardIterator1 last1,
  ForwardIterator2 first2, ForwardIterator2 last2,
  BinaryPredicate pred
  );

Effects

Finds a subsequence of equal values in a sequence.

Returns

The last iterator i in the range [first1,last1 - (last2 - first2)) such that for any nonnegative integer n < (last2 - first2), the following corresponding conditions hold: *(i + n) == *(first2 + n), pred(*(i + n), *(first2 + n)).

Returns last1 if [first2,last2) is empty or if no such iterator is found.

Examples

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

SPROUT_STATIC_CONSTEXPR auto input1 = array<int, 10>{{1, 2, 3, 4, 5, 1, 2, 3, 4, 5}};
SPROUT_STATIC_CONSTEXPR auto input2 = array<int, 3>{{3, 4, 5}};
SPROUT_STATIC_CONSTEXPR auto result = sprout::find_end(begin(input1), end(input1), begin(input2), end(input2));
static_assert(result != end(input1), "found a subsequence equal to input2 from input1.");
static_assert(result - begin(input1) == 7, "a found position is 7.");

Complexity

At most (last2 - first2) * (last1 - first1 - (last2 - first2) + 1) applications of the corresponding predicate.

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

Header

sprout/algorithm/find_end.hpp

Convenience header: sprout/algorithm.hpp