std::equal
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. |
<metanoindex/>
<tbody> </tbody>| Definido no cabeçalho <algorithm>
|
||
template< class InputIt1, class InputIt2 > bool equal( InputIt1 first1, InputIt1 last1, InputIt2 first2 ); |
(1) | |
template< class InputIt1, class InputIt2, class BinaryPredicate > bool equal( InputIt1 first1, InputIt1 last1, InputIt2 first2, BinaryPredicate p ); |
(2) | |
Retorna
true se os elementos são os mesmos em duas gamas: uma definida por [first1, last1) e outra a partir de first2. A primeira versão da função usa operator== para comparar os elementos, o segundo usa o predicado binário dado p.Original:
Returns
true if the elements are the same in two ranges: one defined by [first1, last1) and another starting at first2. The first version of the function uses operator== to compare the elements, the second 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
| first1, last1 | - | a primeira gama de elementos para comparar
Original: the first range of the elements to compare The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| first2 | - | no início do segundo intervalo de elementos para comparar
Original: beginning of the second range of the elements to compare 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 | ||
-InputIt1, InputIt2 must meet the requirements of InputIterator.
| ||
Valor de retorno
true se os elementos dos dois intervalos são iguaisOriginal:
true if the elements in the two ranges are equalThe 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.
Notas
std::equal não pode ser usado para comparar os intervalos formados pelos iteradores de std::unordered_set, std::unordered_multiset, std::unordered_map, std::unordered_multimap ou porque a ordem em que os elementos são armazenados nos recipientes podem ser diferentes mesmo se os dois recipientes de armazenar os mesmos elementos. Original:
std::equal may not be used to compare the ranges formed by the iterators from std::unordered_set, std::unordered_multiset, std::unordered_map, or std::unordered_multimap because the order in which the elements are stored in those containers may be different even if the two containers store the same elements. 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.
{{{1}}}
Original:
{{{2}}}
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
No máximo
last1 - first1 aplicações do predicadoOriginal:
At most
last1 - first1 applications of the predicateThe 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 InputIt1, class InputIt2>
bool equal(InputIt1 first1, InputIt1 last1,
InputIt2 first2)
{
for (; first1 != last1; ++first1, ++first2) {
if (!(*first1 == *first2)) {
return false;
}
}
return true;
}
|
| Second version |
template<class InputIt1, class InputIt2, class BinaryPredicate>
bool equal(InputIt1 first1, InputIt1 last1,
InputIt2 first2, BinaryPredicate p)
{
for (; first1 != last1; ++first1, ++first2) {
if (!p(*first1, *first2)) {
return false;
}
}
return true;
}
|
Exemplo
O código a seguir usa
equal() para testar se uma string é um palíndromo
Original:
The following code uses
equal() to test if a string is a palindrome
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 <iostream>
#include <algorithm>
#include <string>
void test(const std::string& s)
{
if(std::equal(s.begin(), s.begin() + s.size()/2, s.rbegin())) {
std::cout << "\"" << s << "\" is a palindrome\n";
} else {
std::cout << "\"" << s << "\" is not palindrome\n";
}
}
int main()
{
test("radar");
test("hello");
}
Saída:
"radar" is a palindrome
"hello" is not palindrome
(C++11) |
encontra o primeiro elemento satisfazer critérios específicos Original: finds the first element satisfying specific criteria 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 true se um intervalo é lexicograficamente menor do que outro Original: returns true if one range is lexicographically less than another 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) | |
encontra a primeira posição em que dois intervalos diferentes Original: finds the first position where two ranges differ 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) | |
| searches for a range of elements (modelo de função) | |