std::unique_copy
De cppreference.com
| Definido en el archivo de encabezado <algorithm>
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template< class InputIt, class OutputIt >
ForwardIt unique_copy( InputIt first, InputIt last,
OutputIt d_first );
|
(1) | |
template< class InputIt, class OutputIt, class BinaryPredicate >
ForwardIt unique_copy( InputIt first, InputIt last,
OutputIt d_first, BinaryPredicate p );
|
(2) | |
Copia los elementos de la
[first, last) rango, a otro principio rango en d_first de tal manera que no hay elementos iguales consecutivos. Sólo el primer elemento de cada grupo de elementos iguales se copia. La primera versión utiliza operator== para comparar los elementos, la segunda versión utiliza el predicado binario dado p .Original:
Copies the elements from the range
[first, last), to another range beginning at d_first in such a way that there are no consecutive equal elements. Only the first element of each group of equal elements is copied. 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.
Parámetros
| first, last | - | el intervalo de elementos de proceso
Original: the range of elements to process The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| d_first | - | el comienzo del rango de destino
Original: the beginning of the destination range The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| p | - | Predicado binario que devuelve true si los elementos deben tratarse como iguales. La signatura de la función predicado deberá ser equivalente a la siguiente:
Mientras que la signatura no necesita tener |
| Requisitos de tipo | ||
-InputIt debe reunir los requerimientos de InputIterator.
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-OutputIt debe reunir los requerimientos de OutputIterator.
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-The type of dereferenced InputIt must meet the requirements of CopyAssignable.
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-The type of dereferenced InputIt must meet the requirements of CopyConstructible. if neither InputIt nor OutputIt satisfies ForwardIterator
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Valor de retorno
Salida de iterador al elemento más allá del último elemento escrito
Original:
Output iterator to the element past the last written element
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.
Posible implementación
| Primera versión |
|---|
template<class ForwardIt, class OutputIt>
ForwardIt unique_copy(ForwardIt first, ForwardIt last,
OutputIt d_first)
{
if (first == last)
return d_first;
*d_first = *first;
while (++first != last) {
if (!(*d_first == *first)) {
*(++d_first) = *first;
}
}
return ++d_first;
}
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| Segunda versión |
template<class ForwardIt, class OutputIt, class BinaryPredicate>
ForwardIt unique_copy(ForwardIt first, ForwardIt last,
OutputIt d_first, BinaryPredicate p)
{
if (first == last)
return d_first;
*d_first = *first;
while (++first != last) {
if (!p(*result, *first)) {
*(++d_first) = *first;
}
}
return ++d_first;
}
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Ejemplo
Los adornos de los siguientes programas todos los múltiples espacios consecutivos en una cadena constante e imprime el resultado
Original:
The following program trims all multiple consecutive spaces in a const string and prints the result
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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Ejecuta este código
#include <string>
#include <iostream>
#include <algorithm>
#include <iterator>
int main()
{
std::string s1 = "The string with many spaces!";
std::cout << "before: " << s1 << '\n';
std::string s2;
std::unique_copy(s1.begin(), s1.end(), std::back_inserter(s2),
[](char c1, char c2){ return c1 == ' ' && c2 == ' '; });
std::cout << "after: " << s2 << '\n';
}
Salida:
before: The string with many spaces!
after: The string with many spaces!
Complejidad
lineal en la distancia entre
first y lastOriginal:
linear in the distance between
first and lastThe 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.