28 Algorithms library [algorithms]

28.7 Sorting and related operations [alg.sorting]

28.7.1 Sorting [alg.sort]

28.7.1.1 sort [sort]

template<class RandomAccessIterator> void sort(RandomAccessIterator first, RandomAccessIterator last); template<class ExecutionPolicy, class RandomAccessIterator> void sort(ExecutionPolicy&& exec, RandomAccessIterator first, RandomAccessIterator last); template<class RandomAccessIterator, class Compare> void sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp); template<class ExecutionPolicy, class RandomAccessIterator, class Compare> void sort(ExecutionPolicy&& exec, RandomAccessIterator first, RandomAccessIterator last, Compare comp);

1
#

Requires: RandomAccessIterator shall satisfy the requirements of ValueSwappable. The type of *first shall satisfy the requirements of MoveConstructible and of MoveAssignable.

2
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Effects: Sorts the elements in the range [first, last).

3
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Complexity: O(NlogN) comparisons, where N=last - first.

28.7.1.2 stable_­sort [stable.sort]

template<class RandomAccessIterator> void stable_sort(RandomAccessIterator first, RandomAccessIterator last); template<class ExecutionPolicy, class RandomAccessIterator> void stable_sort(ExecutionPolicy&& exec, RandomAccessIterator first, RandomAccessIterator last); template<class RandomAccessIterator, class Compare> void stable_sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp); template<class ExecutionPolicy, class RandomAccessIterator, class Compare> void stable_sort(ExecutionPolicy&& exec, RandomAccessIterator first, RandomAccessIterator last, Compare comp);

1
#

Requires: RandomAccessIterator shall satisfy the requirements of ValueSwappable. The type of *first shall satisfy the requirements of MoveConstructible and of MoveAssignable.

2
#

Effects: Sorts the elements in the range [first, last).

3
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Complexity: At most Nlog2(N) comparisons, where N=last - first, but only NlogN comparisons if there is enough extra memory.

4
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Remarks: Stable.

28.7.1.3 partial_­sort [partial.sort]

template<class RandomAccessIterator> void partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last); template<class ExecutionPolicy, class RandomAccessIterator> void partial_sort(ExecutionPolicy&& exec, RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last); template<class RandomAccessIterator, class Compare> void partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last, Compare comp); template<class ExecutionPolicy, class RandomAccessIterator, class Compare> void partial_sort(ExecutionPolicy&& exec, RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last, Compare comp);

1
#

Requires: RandomAccessIterator shall satisfy the requirements of ValueSwappable. The type of *first shall satisfy the requirements of MoveConstructible and of MoveAssignable.

2
#

Effects: Places the first middle - first sorted elements from the range [first, last) into the range [first, middle). The rest of the elements in the range [middle, last) are placed in an unspecified order.

3
#

Complexity: Approximately (last - first) * log(middle - first) comparisons.

28.7.1.4 partial_­sort_­copy [partial.sort.copy]

template<class InputIterator, class RandomAccessIterator> RandomAccessIterator partial_sort_copy(InputIterator first, InputIterator last, RandomAccessIterator result_first, RandomAccessIterator result_last); template<class ExecutionPolicy, class ForwardIterator, class RandomAccessIterator> RandomAccessIterator partial_sort_copy(ExecutionPolicy&& exec, ForwardIterator first, ForwardIterator last, RandomAccessIterator result_first, RandomAccessIterator result_last); template<class InputIterator, class RandomAccessIterator, class Compare> RandomAccessIterator partial_sort_copy(InputIterator first, InputIterator last, RandomAccessIterator result_first, RandomAccessIterator result_last, Compare comp); template<class ExecutionPolicy, class ForwardIterator, class RandomAccessIterator, class Compare> RandomAccessIterator partial_sort_copy(ExecutionPolicy&& exec, ForwardIterator first, ForwardIterator last, RandomAccessIterator result_first, RandomAccessIterator result_last, Compare comp);

1
#

Requires: RandomAccessIterator shall satisfy the requirements of ValueSwappable. The type of *result_­first shall satisfy the requirements of MoveConstructible and of MoveAssignable.

2
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Effects: Places the first min(last - first, result_­last - result_­first) sorted elements into the range [result_­first, result_­first + min(last - first, result_­last - result_­first)).

3
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Returns: The smaller of: result_­last or result_­first + (last - first).

4
#

Complexity: Approximately (last - first) * log(min(last - first, result_­last - result_­first)) comparisons.

28.7.1.5 is_­sorted [is.sorted]

template<class ForwardIterator> bool is_sorted(ForwardIterator first, ForwardIterator last);

1
#

Returns: is_­sorted_­until(first, last) == last

template<class ExecutionPolicy, class ForwardIterator> bool is_sorted(ExecutionPolicy&& exec, ForwardIterator first, ForwardIterator last);

2
#

Returns: is_­sorted_­until(std​::​forward<ExecutionPolicy>(exec), first, last) == last

template<class ForwardIterator, class Compare> bool is_sorted(ForwardIterator first, ForwardIterator last, Compare comp);

3
#

Returns: is_­sorted_­until(first, last, comp) == last

template<class ExecutionPolicy, class ForwardIterator, class Compare> bool is_sorted(ExecutionPolicy&& exec, ForwardIterator first, ForwardIterator last, Compare comp);

4
#

Returns: 

is_sorted_until(std::forward<ExecutionPolicy>(exec), first, last, comp) == last

template<class ForwardIterator> ForwardIterator is_sorted_until(ForwardIterator first, ForwardIterator last); template<class ExecutionPolicy, class ForwardIterator> ForwardIterator is_sorted_until(ExecutionPolicy&& exec, ForwardIterator first, ForwardIterator last); template<class ForwardIterator, class Compare> ForwardIterator is_sorted_until(ForwardIterator first, ForwardIterator last, Compare comp); template<class ExecutionPolicy, class ForwardIterator, class Compare> ForwardIterator is_sorted_until(ExecutionPolicy&& exec, ForwardIterator first, ForwardIterator last, Compare comp);

5
#

Returns: If (last - first) < 2, returns last. Otherwise, returns the last iterator i in [first, last] for which the range [first, i) is sorted.

6
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Complexity: Linear.