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Added shell and insertion sort (insertion sort to be optimised for pointers & PODs)

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Call specific sorts from sort() and stable_sort()
This commit is contained in:
John Wellbelove 2019-11-13 13:16:45 +00:00
parent a84a88d7e8
commit 8509df67c7
1 changed files with 125 additions and 3 deletions
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128
include/etl/algorithm.h
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@ -1124,12 +1124,17 @@ namespace etl
//***************************************************************************
/// Sorts the elements using shell sort.
/// Uses users defined comparison.
/// Uses user defined comparison.
///\ingroup algorithm
//***************************************************************************
template <typename TIterator, typename TCompare>
void sort(TIterator first, TIterator last, TCompare compare)
void shell_sort(TIterator first, TIterator last, TCompare compare)
{
if (first == last)
{
return;
}
typedef typename ETLSTD::iterator_traits<TIterator>::difference_type difference_t;
difference_t n = ETLSTD::distance(first, last);
@ -1160,9 +1165,126 @@ namespace etl
///\ingroup algorithm
//***************************************************************************
template <typename TIterator>
void shell_sort(TIterator first, TIterator last)
{
etl::shell_sort(first, last, ETLSTD::less<typename ETLSTD::iterator_traits<TIterator>::value_type>());
}
//***************************************************************************
/// Sorts the elements using insertion sort.
/// Uses user defined comparison.
///\ingroup algorithm
//***************************************************************************
// Pointers and PODs.
template <typename TIterator, typename TCompare>
typename etl::enable_if<etl::is_pointer<TIterator>::value &&
etl::is_pointer<TIterator>::value &&
etl::is_pod<typename ETLSTD::iterator_traits<TIterator>::value_type>::value, void>::type
insertion_sort(TIterator first, TIterator last, TCompare compare)
{
//#############################################################################
// OPTIMISE THIS FOR POINTERS AND PODS USING MEMMOVE OR COPY_BACKWARD
//#############################################################################
typedef typename ETLSTD::iterator_traits<TIterator>::value_type value_type;
TIterator a = first;
if (a == last)
{
return;
}
ETLSTD::iter_swap(first, ETLSTD::min_element(a, last));
for (TIterator b = a; ++b < last; a = b)
{
for (TIterator c = b; compare(*c, *a); --c, a -= (a != first))
{
ETLSTD::iter_swap(a, c);
}
}
}
// Other types.
template <typename TIterator, typename TCompare>
typename etl::enable_if<!etl::is_pointer<TIterator>::value ||
!etl::is_pointer<TIterator>::value ||
!etl::is_pod<typename ETLSTD::iterator_traits<TIterator>::value_type>::value, void>::type
insertion_sort(TIterator first, TIterator last, TCompare compare)
{
typedef typename ETLSTD::iterator_traits<TIterator>::value_type value_type;
TIterator a = first;
if (a == last)
{
return;
}
ETLSTD::iter_swap(first, ETLSTD::min_element(a, last));
for (TIterator b = a; ++b < last; a = b)
{
for (TIterator c = b; compare(*c, *a); --c, a -= (a != first))
{
ETLSTD::iter_swap(a, c);
}
}
}
//***************************************************************************
/// Sorts the elements using insertion sort.
///\ingroup algorithm
//***************************************************************************
template <typename TIterator>
void insertion_sort(TIterator first, TIterator last)
{
etl::insertion_sort(first, last, ETLSTD::less<typename ETLSTD::iterator_traits<TIterator>::value_type>());
}
//***************************************************************************
/// Sorts the elements.
/// Uses user defined comparison.
///\ingroup algorithm
//***************************************************************************
template <typename TIterator, typename TCompare>
void sort(TIterator first, TIterator last, TCompare compare)
{
etl::shell_sort(first, last, compare);
}
//***************************************************************************
/// Sorts the elements.
///\ingroup algorithm
//***************************************************************************
template <typename TIterator>
void sort(TIterator first, TIterator last)
{
etl::sort(first, last, ETLSTD::less<typename ETLSTD::iterator_traits<TIterator>::value_type>());
etl::shell_sort(first, last, ETLSTD::less<typename ETLSTD::iterator_traits<TIterator>::value_type>());
}
//***************************************************************************
/// Sorts the elements.
/// Stable.
/// Uses user defined comparison.
///\ingroup algorithm
//***************************************************************************
template <typename TIterator, typename TCompare>
void stable_sort(TIterator first, TIterator last, TCompare compare)
{
etl::insertion_sort(first, last, compare);
}
//***************************************************************************
/// Sorts the elements.
/// Stable.
///\ingroup algorithm
//***************************************************************************
template <typename TIterator>
void stable_sort(TIterator first, TIterator last)
{
etl::insertion_sort(first, last, ETLSTD::less<typename ETLSTD::iterator_traits<TIterator>::value_type>());
}
#if ETL_CPP11_SUPPORTED