std::nth_element
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definiert in Header <algorithm>
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template< class RandomIt > void nth_element( RandomIt first, RandomIt nth, RandomIt last ); |
(1) | |
template< class RandomIt, class Compare > void nth_element( RandomIt first, RandomIt nth, RandomIt last, Compare comp ); |
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Teilweise Arten der Bereich
[first, last)
in aufsteigender Reihenfolge, so dass alle Elemente im Bereich [first, nth)
sind weniger als diejenigen im Bereich [nth, last)
. Die erste Version verwendet operator< um die Elemente zu vergleichen, verwendet die zweite Version des gegebenen Vergleichsfunktion comp
. Das Element in der Position platziert nth
ist genau das Element, welches in dieser Position auftreten würde, wenn der Bereich vollständig sortiert wurde .Original:
Partially sorts the range
[first, last)
in ascending order so that all elements in the range [first, nth)
are less than those in the range [nth, last)
. The first version uses operator< to compare the elements, the second version uses the given comparison function comp
. The element placed in the nth
position is exactly the element that would occur in this position if the range was fully sorted.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
Inhaltsverzeichnis |
[Bearbeiten] Parameter
first, last | - | Random-Access-Iteratoren definieren den Bereich sort
Original: random access iterators defining the range sort The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
nth | - | Random Access Iterator definieren die Art Partition Punkt
Original: random access iterator defining the sort partition point The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
comp | - | comparison function which returns true if the first argument is less than the second. The signature of the comparison function should be equivalent to the following: bool cmp(const Type1 &a, const Type2 &b); The signature does not need to have const &, but the function must not modify the objects passed to it. |
Type requirements | ||
-RandomIt must meet the requirements of ValueSwappable and RandomAccessIterator .
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-The type of dereferenced RandomIt must meet the requirements of MoveAssignable and MoveConstructible .
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[Bearbeiten] Rückgabewert
(None)
Original:
(none)
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[Bearbeiten] Komplexität
Linear in std::distance(first, last) im Durchschnitt .
Original:
Linear in std::distance(first, last) on average.
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[Bearbeiten] Beispiel
#include <iostream> #include <vector> #include <algorithm> #include <functional> int main() { std::vector<int> v{5, 6, 4, 3, 2, 6, 7, 9, 3}; std::nth_element(v.begin(), v.begin() + v.size()/2, v.end()); std::cout << "The median is " << v[v.size()/2] << '\n'; std::nth_element(v.begin(), v.begin()+1, v.end(), std::greater<int>()); std::cout << "The second largest element is " << v[1] << '\n'; }
Output:
The median is 5 The second largest element is 7
[Bearbeiten] Siehe auch
Kopien und teilweise Arten eine Reihe von Elementen Original: copies and partially sorts a range of elements The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Funktions-Template) | |
Arten eine Reihe von Elementen, während Aufrechterhaltung der Ordnung zwischen gleichen Elementen Original: sorts a range of elements while preserving order between equal elements The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Funktions-Template) | |
Sortiert einen Bereich in aufsteigender Reihenfolge Original: sorts a range into ascending order The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Funktions-Template) |