std::minmax_element
Da 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. |
| Definido no cabeçalho <algorithm>
|
||
| template< class ForwardIt > std::pair<ForwardIt,ForwardIt> |
(1) | |
| template< class ForwardIt, class Compare > std::pair<ForwardIt,ForwardIt> |
(2) | |
Encontra o maior e o mais pequeno elemento na
[first, last) gama. A primeira versão utiliza operator< para comparar os valores, a segunda versão utiliza a função de comparação dada 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.
Índice |
[editar] Parâmetros
| first, last | - | iteradores para a frente que definem o intervalo para examinar
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.
| ||
[editar] Valor de retorno
um par consistindo de uma iteração para o elemento mais pequeno, como o primeiro elemento e um iterador para o elemento maior que a segunda. Retorna std::make_pair(first, first) se o intervalo está vazio. Se vários elementos são equivalentes ao elemento mais pequeno, o iterador para o primeiro elemento tal é retornada. Se vários elementos são equivalentes ao elemento maior, o iterador para o último elemento tal for devolvido.
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.
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.
[editar] Complexidade
Na maioria das aplicações de max(floor(3/2(N−1)), 0) do predicado, onde 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.
You can help to correct and verify the translation. Click here for instructions.
[editar] Possível implementação
| First version |
|---|
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; } |
[editar] Exemplo
#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'; }
Saída:
min element at: 2 max element at: 6
[editar] Veja também
| retorna o elemento mais pequeno de um intervalo 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. (modelo de função) | |
| retorna o maior elemento de um intervalo 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. (modelo de função) | |
