binary_search

Interface

template<typename ForwardIterator, typename T>
inline SPROUT_CONSTEXPR bool
binary_search(ForwardIterator first, ForwardIterator last, T const& value);

template<typename ForwardIterator, typename T, typename Compare>
inline SPROUT_CONSTEXPR bool
binary_search(ForwardIterator first, ForwardIterator last, T const& value, Compare comp);

Requires

The elements e of [first,last) are partitioned with respect to the expressions e < value and !(value < e) or comp(e, value) and !comp(value, e).

Also, for all elements e of [first,last), e < value implies !(value < e) or comp(e, value) implies !comp(value, e).

Returns

true if there is an iterator i in the range [first,last) that satisfies the corresponding conditions: !(*i < value) && !(value < *i) or comp(*i, value) && comp(value, *i).

Examples

#include <sprout/algorithm/binary_search.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, 5, 5, 8, 9, 10}};
SPROUT_STATIC_CONSTEXPR auto result = sprout::binary_search(begin(input), end(input), 5);
static_assert(result, "found 5 by binary search.");

Complexity

At most log2(last - first) + O(1) comparisons.

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

Header

sprout/algorithm/binary_search.hpp

Convenience header: sprout/algorithm.hpp