std::find_first_of
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<metanoindex/>
<tbody> </tbody>| Definido no cabeçalho <algorithm>
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template< class ForwardIt1, class ForwardIt2 > ForwardIt1 find_first_of( ForwardIt1 first, ForwardIt1 last, ForwardIt2 s_first, ForwardIt2 s_last ); template< class InputIt, class ForwardIt > InputIt find_first_of( InputIt first, InputIt last, ForwardIt s_first, ForwardIt s_last ); |
(1) | (até C++11) (desde C++11) |
template< class ForwardIt1, class ForwardIt2, class BinaryPredicate > ForwardIt1 find_first_of( ForwardIt1 first, ForwardIt1 last, ForwardIt2 s_first, ForwardIt2 s_last, BinaryPredicate p ); template< class InputIt, class ForwardIt, class BinaryPredicate > InputIt find_first_of( InputIt first, InputIt last, ForwardIt s_first, ForwardIt s_last, BinaryPredicate p ); |
(2) | (até C++11) (desde C++11) |
Pesquisa o
[first, last) gama para qualquer um dos elementos na [s_first, s_last) gama. A primeira versão utiliza operator== para comparar os elementos, a segunda versão usa o predicado binário dado p. Original:
Searches the range
[first, last) for any of the elements in the range [s_first, s_last). The first version uses operator== to compare the elements, the second version uses the given binary predicate p. 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.
Parâmetros
| first, last | - | a gama de elementos para examinar
Original: the range of elements to examine The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| s_first, s_last | - | a gama de elementos para pesquisar
Original: the range of elements to search for The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| p | - | binary predicate which returns true if the elements should be treated as equal. The signature of the predicate function should be equivalent to the following:
The signature does not need to have |
| Type requirements | ||
-InputIt must meet the requirements of InputIterator.
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-ForwardIt1 must meet the requirements of ForwardIterator.
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-ForwardIt2 must meet the requirements of ForwardIterator.
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Valor de retorno
Iterador para o primeiro elemento na
[first, last) intervalo que é igual a um elemento da [s_first; s_last) gama. Se nenhum elemento for encontrado, é retornado last.Original:
Iterator to the first element in the range
[first, last) that is equal to an element from the range [s_first; s_last). If no such element is found, last 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.
Complexidade
Será que a maioria das comparações dos
(S*N) onde S = distance(s_first, s_last) e N = distance(first, last).Original:
Does at most
(S*N) comparisons where S = distance(s_first, s_last) and N = 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.
Possível implementação
| First version |
|---|
template<class InputIt, class ForwardIt>
InputIt find_first_of(InputIt first, InputIt last,
ForwardIt s_first, ForwardIt s_last)
{
for (; first != last; ++first) {
for (ForwardIt it = s_first; it != s_last; ++it) {
if (*first == *it) {
return first;
}
}
}
return last;
}
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| Second version |
template<class InputIt, class ForwardIt, class BinaryPredicate>
InputIt find_first_of(InputIt first, InputIt last,
ForwardIt s_first, ForwardIt s_last,
BinaryPredicate p)
{
for (; first != last; ++first) {
for (ForwardIt it = s_first; it != s_last; ++it) {
if (p(*first, *it)) {
return first;
}
}
}
return last;
}
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Exemplo
As seguintes pesquisas de código para qualquer um dos números inteiros especificados em um vetor de números inteiros:
Original:
The following code searches for any of specified integers in a vector of integers:
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.
#include <algorithm>
#include <iostream>
#include <vector>
int main()
{
std::vector<int> v{0, 2, 3, 25, 5};
std::vector<int> t{3, 19, 10, 2};
auto result = std::find_first_of(v.begin(), v.end(), t.begin(), t.end());
if (result == v.end()) {
std::cout << "no elements of v were equal to 3, 19, 10 or 2\n";
} else {
std::cout << "found a match at "
<< std::distance(v.begin(), result) << "\n";
}
}
Saída:
found a match at 1