std::max_element
De cppreference.com
 [] |
This page has been machine-translated from the English version of the wiki using Google Translate.
The translation may contain errors and awkward wording. Hover over text to see the original version. You can help to fix errors and improve the translation. For instructions click here. |
![[]](https://upload.cppreference.com/mwiki/images/3/31/Imbox_notice.png){kind=link}
<metanoindex/>
<tbody> </tbody>| Dclar dans l'en-tte <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) | |
Trouve le plus grand lment de la gamme
[first, last). La premire version utilise operator< de comparer les valeurs, la deuxime version utilise la fonction de comparaison donne comp .Original:
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.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.
Paramtres
| first, last | - | itrateurs terme dfinissant la plage d'examiner
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:
The signature does not need to have |
| Type requirements | ||
-ForwardIt must meet the requirements of ForwardIterator.
| ||
Retourne la valeur
Iterator pour le plus grand lment de la gamme
[first, last). Si plusieurs lments de la gamme sont quivalentes au plus grand lment, retourne l'itrateur sur le premier lment tel. Retours last si la plage est vide . Original:
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. 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.
Complexit
Exactement max(N-1,0) comparaisons, o
N = std::distance(first, last) .Original:
Exactly max(N-1,0) comparisons, 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.
You can help to correct and verify the translation. Click here for instructions.
Mise en uvre possible
| 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;
}
|
Exemple
#include <algorithm>
#include <iostream>
#include <vector>
#include <cmath>
static bool 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);
}
Rsultat :
max element at: 5
max element (absolute) at: 2
Voir aussi
retourne le plus petit lment dans une plage 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. (fonction gnrique) | |
(C++11) |
retourne le plus petit lment et le plus important dans une gamme 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. (fonction gnrique) |
retourne le plus grand des deux lments 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. (fonction gnrique) | |