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54 lines
1.9 KiB
ReStructuredText
54 lines
1.9 KiB
ReStructuredText
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.. _sprout-algorithm-binary_search:
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###############################################################################
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binary_search
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###############################################################################
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Interface
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========================================
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.. sourcecode:: c++
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template<typename ForwardIterator, typename T>
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inline SPROUT_CONSTEXPR bool
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binary_search(ForwardIterator first, ForwardIterator last, T const& value);
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template<typename ForwardIterator, typename T, typename Compare>
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inline SPROUT_CONSTEXPR bool
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binary_search(ForwardIterator first, ForwardIterator last, T const& value, Compare comp);
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Requires
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========================================
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| 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)``.
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| Also, for all elements e of [first,last), ``e < value`` implies ``!(value < e)`` or ``comp(e, value)`` implies ``!comp(value, e)``.
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Returns
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========================================
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| 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)``.
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Examples
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========================================
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.. sourcecode:: c++
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#include <sprout/algorithm/binary_search.hpp>
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#include <sprout/array.hpp>
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#include <sprout/container.hpp>
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using namespace sprout;
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SPROUT_STATIC_CONSTEXPR auto input = array<int, 10>{{1, 2, 3, 5, 5, 5, 5, 8, 9, 10}};
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SPROUT_STATIC_CONSTEXPR auto result = sprout::binary_search(begin(input), end(input), 5);
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static_assert(result, "found 5 by binary search.");
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Complexity
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========================================
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| At most ``log2(last - first) + O(1)`` comparisons.
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| Recursive function invocations in *O(logN)* (logarithmic) depth.
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Header
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========================================
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| ``sprout/algorithm/binary_search.hpp``
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| Convenience header: ``sprout/algorithm.hpp``
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