mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
synced 2024-11-25 00:43:44 +00:00
54 lines
1.9 KiB
ReStructuredText
54 lines
1.9 KiB
ReStructuredText
|
.. _sprout-algorithm-binary_search:
|
||
|
|
###############################################################################
|
||
|
|
binary_search
|
||
|
|
###############################################################################
|
||
|
|
|
||
|
|
Interface
|
||
|
|
========================================
|
||
|
|
.. sourcecode:: c++
|
||
|
|
|
||
|
|
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
|
||
|
|
========================================
|
||
|
|
.. sourcecode:: c++
|
||
|
|
|
||
|
|
#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``
|
||
|
|
|