std::max_element
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definiert in Header <algorithm> | ||
template<class ForwardIt > ForwardIt max_element( ForwardIt first, ForwardIt last ); | (1) | |
template<class ForwardIt, class Compare > ForwardIt max_element( ForwardIt first, ForwardIt last, Compare comp ); | (2) | |
Finds the greatest element in the range [first, last)
. The first version uses operator< to compare the values, the second version uses the given comparison function comp
.
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 . |
[Bearbeiten]Rückgabewert
Iterator to the greatest element in the range [first, last)
. If several elements in the range are equivalent to the greatest element, returns the iterator to the first such element. Returns last
if the range is empty.
[Bearbeiten]Komplexität
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[Bearbeiten]Mögliche Implementierung
First version |
---|
template<class ForwardIt> ForwardIt max_element(ForwardIt first, ForwardIt last){if(first == last){return last;} ForwardIt largest = first;++first;for(; first != last;++first){if(*largest <*first){ largest = first;}}return largest;} |
Second version |
template<class ForwardIt, class Compare> ForwardIt max_element(ForwardIt first, ForwardIt last, Compare comp){if(first == last){return last;} ForwardIt largest = first;++first;for(; first != last;++first){if(comp(*largest, *first)){ largest = first;}}return largest;} |
[Bearbeiten]Beispiel
#include <algorithm>#include <iostream>#include <vector>#include <cmath> staticbool abs_compare(int a, int b){return(std::abs(a)< std::abs(b));} int main(){std::vector<int> v{3, 1, -14, 1, 5, 9};std::vector<int>::iterator result; result = std::max_element(v.begin(), v.end());std::cout<<"max element at: "<<std::distance(v.begin(), result)<<'\n'; result = std::max_element(v.begin(), v.end(), abs_compare);std::cout<<"max element (absolute) at: "<<std::distance(v.begin(), result);}
Output:
max element at: 5 max element (absolute) at: 2
[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) | |
(C++11) | gibt die kleinste und das größte Element in einem Bereich Original: returns the smallest and 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) |
liefert den größeren der beiden Elemente Original: returns the larger of two 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) |