std::upper_bound

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Definido en la cabecera `<algorithm>`
template< class ForwardIt, class T > ForwardIt upper_bound( ForwardIt first, ForwardIt last, const T& value );	(1)
template< class ForwardIt, class T, class Compare > ForwardIt upper_bound( ForwardIt first, ForwardIt last, const T& value, Compare comp );	(2)

Devuelve un iterador que señala al primer elemento en la [first, last) rango que es mayor' que value. La primera versión utiliza operator< para comparar los elementos, la segunda versión utiliza la función de comparación dado comp .
Original:
Returns an iterator pointing to the first element in the range [first, last) that is greater than value. The first version uses operator< to compare the elements, the second version uses the given comparison function comp.
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Contenido

[editar] Parámetros

first, last	-	la gama de elementos a 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.
value	-	valor para comparar los elementos a Original: value to compare the elements to The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
comp	-	comparison function which returns true if the first argument is less than the second. 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. The type Type1 must be such that an object of type T can be implicitly converted to Type1. The type Type2 must be such that an object of type ForwardIt can be dereferenced and then implicitly converted to Type2.
Requerimientos de tipo
- `ForwardIt` debe reunir los requerimientos de `ForwardIterator`.

[editar] Valor de retorno

iterador que señala al primer elemento que es mayor' que value, o last si no se encuentra dicho elemento .
Original:
iterator pointing to the first element that is greater than value, or last if no such element is found.
The text has been machine-translated via Google Translate.
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[editar] Posible implementación

Primera versión

template<class ForwardIt, class T>
ForwardIt upper_bound(ForwardIt first, ForwardIt last,
                            const T& value)
{
    ForwardIt it;
    std::iterator_traits<ForwardIt>::distance_type count, step;
    count = std::distance(first,last);
 
    while (count > 0) {
        it = first; 
        step = count / 2; 
        std::advance(it, step);
        if (!(value < *it)) {
            first = ++it;
            count -= step + 1;
        } else count = step;
    }
    return first;
}

Segunda versión

template<class ForwardIt, class T, class Compare>
ForwardIt upper_bound(ForwardIt first, ForwardIt last,
                            const T& value, Compare comp)
{
    ForwardIt it;
    std::iterator_traits<ForwardIt>::distance_type count, step;
    count = std::distance(first,last);
 
    while (count > 0) {
        it = first; 
        step = count / 2;
        std::advance(it, step);
        if (!comp(value, *it)),
            first = ++it;
            count -= step + 1
        } else count = step;
    }
    return first;
}

[editar] Ejemplo

#include <algorithm>
#include <iostream>
#include <iterator>
#include <vector>
 
int main()
{
    std::vector<int> data = { 1, 1, 2, 3, 3, 3, 3, 4, 4, 4, 5, 5, 6 };
 
    auto lower = std::lower_bound(data.begin(), data.end(), 4);
    auto upper = std::upper_bound(data.begin(), data.end(), 4);
 
    std::copy(lower, upper, std::ostream_iterator<int>(std::cout, " "));
}

Salida:

4 4 4

[editar] Complejidad

logarítmica en la distancia entre first y last

[editar] Ver también

equal_range	El rendimiento es de los elementos que coinciden con una clave específica Original: returns range of elements matching a specific key The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (plantilla de función) [editar]
lower_bound	devuelve un iterador al primer elemento no es menor que el valor dado Original: returns an iterator to the first element not less than the given value The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (plantilla de función) [editar]

Mar	MAY	Jul
	08
2017	2018	2019

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