std::minmax_element
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| definiert in Header <algorithm>
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| template< class ForwardIt > std::pair<ForwardIt,ForwardIt> |
(1) | |
| template< class ForwardIt, class Compare > std::pair<ForwardIt,ForwardIt> |
(2) | |
Findet das größte und das kleinste Element im Bereich
[first, last). Die erste Version verwendet operator< um die Werte zu vergleichen, verwendet die zweite Version des gegebenen Vergleichsfunktion comp .Original:
Finds the greatest and the smallest element in the range
[first, last). The first version uses operator< to compare the values, the second version uses the given comparison function comp.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 | - | Vorwärts Iteratoren definieren den Bereich zu prüfen
Original: forward iterators defining the range to examine The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| cmp | - | comparison function which returns true if if *a is less than *b. 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 | ||
-ForwardIt must meet the requirements of ForwardIterator.
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[Bearbeiten] Rückgabewert
ein Paar bestehend aus einem Iterator zum kleinsten Element wie das erste Element und einem Iterator zum größten Element als die zweite. Versandkosten std::make_pair(first, first) wenn der Bereich leer. Wenn mehrere Elemente entspricht der kleinsten Elements sind, wird der Iterator das erste Element zurück. Wenn mehrere Elemente äquivalent zu der größte Element sind, wird der Iterator zur letzten solches Element zurückgegeben .
Original:
a pair consisting of an iterator to the smallest element as the first element and an iterator to the greatest element as the second. Returns std::make_pair(first, first) if the range is empty. If several elements are equivalent to the smallest element, the iterator to the first such element is returned. If several elements are equivalent to the largest element, the iterator to the last such element is returned.
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[Bearbeiten] Komplexität
An den meisten max(floor(3/2(N−1)), 0) Anwendungen des Prädikats, wo N = std::distance(first, last) .
Original:
At most max(floor(3/2(N−1)), 0) applications of the predicate, where N = std::distance(first, last).
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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[Bearbeiten] Mögliche Implementierung
| First version |
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template<class ForwardIt> std::pair<ForwardIt, ForwardIt> minmax_element(ForwardIt first, ForwardIt last) { typedef typename std::iterator_traits<ForwardIt>::value_type value_t; return std::minmax_element(first, last, std::less<value_t>()); } |
| Second version |
template<class ForwardIt, class Compare> std::pair<ForwardIt, ForwardIt> minmax_element(ForwardIt first, ForwardIt last, Compare comp) { std::pair<ForwardIt, ForwardIt> result(first, first); if (first == last) return result; if (++first == last) return result; if (comp(*first, *result.first)) { result.second = result.first; result.first = first; } else { result.second = first; } while (++first != last) { ForwardIt i = first; if (++first == last) { if (comp(*i, *result.first)) result.first = i; else if (!(comp(*i, *result.second))) result.second = i; break; } else { if (comp(*first, *i)) { if (comp(*first, *result.first)) result.first = first; if (!(comp(*i, *result.second))) result.second = i; } else { if (comp(*i, *result.first)) result.first = i; if (!(comp(*first, *result.second))) result.second = first; } } } return result; } |
[Bearbeiten] Beispiel
#include <algorithm> #include <iostream> #include <vector> int main() { std::vector<int> v = { 3, 9, 1, 4, 2, 5, 9 }; auto result = std::minmax_element(v.begin(), v.end()); std::cout << "min element at: " << (result.first - v.begin()) << '\n'; std::cout << "max element at: " << (result.second - v.begin()) << '\n'; }
Output:
min element at: 2 max element at: 6
[Bearbeiten] Siehe auch
| gibt das kleinste Element in einem Bereich Original: returns the smallest element in a range The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Funktions-Template) | |
| kehrt das größte Element in einem Bereich Original: returns the largest element in a range The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Funktions-Template) | |
