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std::find_first_of

De cppreference.com
< cpp‎ | algorithm

 
 
Biblioteca de algoritmos
Políticas de ejecución (C++17)
Operaciones no modificadoras de secuencia
(C++11)(C++11)(C++11)
(C++17)
find_first_of
Operaciones modificadoras de secuencia
Operaciones en almacenamiento no inicializado
Operaciones de partición
Operaciones de ordenación
(C++11)
Operaciones de búsqueda binaria
Operaciones de set (en rangos ordenados)
Operaciones de pila
(C++11)
Operaciones minimo/maximo
(C++11)
(C++17)
Permutaciones
Operaciones numéricas
Bibliotecas C
 
Definido en la cabecera <algorithm>
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) (hasta 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) (hasta C++11)


(desde C++11)
Busca en la gama [first, last) para cualquiera de los elementos en el rango [s_first, s_last). La primera versión utiliza operator== para comparar los elementos, la segunda versión utiliza el predicado binario 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.
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Contenido

[editar] Parámetros

first, last -
la gama de elementos a examinar
Original:
the range of elements to examine
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s_first, s_last -
la gama de elementos a buscar
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:

 bool pred(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.
The types Type1 and Type2 must be such that objects of types ForwardIt1 and ForwardIt2 can be dereferenced and then implicitly converted to Type1 and Type2 respectively.

Requerimientos de tipo
-
InputIt debe reunir los requerimientos de InputIterator.
-
ForwardIt1 debe reunir los requerimientos de ForwardIterator.
-
ForwardIt2 debe reunir los requerimientos de ForwardIterator.

[editar] Valor de retorno

Iterador al primer elemento en la [first, last) rango que es igual a un elemento de la [s_first; s_last) rango. Si no se encuentra dicho elemento, se devuelve 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.
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[editar] Complejidad

¿Tiene en la mayoría de las comparaciones (S*N) donde S = distance(s_first, s_last) y N = distance(first, last) .
Original:
Does at most (S*N) comparisons where S = distance(s_first, s_last) and N = distance(first, last).
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[editar] Posible implementación

Primera versión
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;
}
Segunda versión
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;
}

[editar] Ejemplo

Las búsquedas de código siguientes para cualquiera de enteros indicados en un vector de enteros:
Original:
The following code searches for any of specified integers in a vector of integers:
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#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";
    }
 }

Salida:

found a match at 1

[editar] Ver también

encuentra el primer elemento que satisfaga los criterios específicos
Original:
finds the first element satisfying specific criteria
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You can help to correct and verify the translation. Click here for instructions.

(plantilla de función) [editar]