Espaços nominais
Variantes
Acções

std::partition

Da cppreference.com
< cpp‎ | algorithm

 
 
Biblioteca algoritmo
Funções
Original:
Functions
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Não modificar operações de seqüência
Original:
Non-modifying sequence operations
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Modificando operações de seqüência
Original:
Modifying sequence operations
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Particionamento operações
Original:
Partitioning operations
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
is_partitioned(C++11)
partition
partition_copy(C++11)
Operações de classificação (em intervalos ordenados)
Original:
Sorting operations (on sorted ranges)
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Binários operações de busca (em intervalos ordenados)
Original:
Binary search operations (on sorted ranges)
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Definir operações (em intervalos ordenados)
Original:
Set operations (on sorted ranges)
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Operações de pilha
Original:
Heap operations
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Mínimo / máximo de operações
Original:
Minimum/maximum operations
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Operações numéricas
Original:
Numeric operations
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
C biblioteca
Original:
C library
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
 
Defined in header <algorithm>
template< class BidirIt, class UnaryPredicate >

BidirectionalIterator partition( BidirIt first, BidirIt last,
                                 UnaryPredicate p );
template< class ForwardIt, class UnaryPredicate >
ForwardIt partition( ForwardIt first, ForwardIt last,

                     UnaryPredicate p );
(até C + 11)

(a partir do C++ 11)
Reordena os elementos na [first, last) faixa, de tal modo que todos os elementos para os quais o predicado p retornos true precedem os elementos para os quais predicado p retornos false. Ordem relativa dos elementos não é preservada.
Original:
Reorders the elements in the range [first, last) in such a way that all elements for which the predicate p returns true precede the elements for which predicate p returns false. Relative order of the elements is not preserved.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

Índice

[editar] Parâmetros

first, last -
a gama de elementos para reordenar
Original:
the range of elements to reorder
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
p - unary predicate which returns ​true
se o elemento deve ser solicitado antes de outros elementos
Original:
if the element should be ordered before other elements
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
.

The signature of the predicate function should be equivalent to the following:

 bool pred(const Type &a);

The signature does not need to have const &, but the function must not modify the objects passed to it.
The type Type must be such that an object of type ForwardIt can be dereferenced and then implicitly converted to Type. ​

Type requirements
-
BidirIt must meet the requirements of BidirectionalIterator.
-
ForwardIt must meet the requirements of ValueSwappable and ForwardIterator. However, the operation is more efficient if ForwardIt also satisfies the requirements of BidirectionalIterator

[editar] Valor de retorno

Iterador para o primeiro elemento do segundo grupo.
Original:
Iterator to the first element of the second group.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[editar] Complexidade

Exatamente last-first aplicações do predicado e em swaps maioria last-first. Se ForwardIt cumpre os requisitos da BidirectionalIterator em swaps maioria (last-first)/2 são feitas.
Original:
Exactly last-first applications of the predicate and at most last-first swaps. If ForwardIt meets the requirements of BidirectionalIterator at most (last-first)/2 swaps are done.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[editar] Possível implementação

template<class BidirIt, class UnaryPredicate>
BidirIt partition(BidirIt first, BidirIt last, UnaryPredicate p)
{
    while (1) {
        while ((first != last) && p(*first)) {
            ++first;
        }
        if (first == last--) break;
        while ((first != last) && !p(*last)) {
            --last;
        }
        if (first == last) break;
        std::swap(*first++, *last);
    }
    return first;
}

[editar] Exemplo

#include <algorithm>
#include <functional>
#include <iostream>
#include <iterator>
#include <vector>
 
bool is_even(int i) { return i % 2 == 0; }
 
int main()
{
    std::vector<int> v;
    for (int i = 0; i < 10; ++i) v.push_back(i);
 
    std::cout << "Original vector:\n    ";
    std::copy(v.begin(), v.end(), std::ostream_iterator<int>(std::cout, " "));
 
    // Partition the vector
    std::vector<int>::iterator p =
        std::partition(v.begin(), v.end(), std::ptr_fun(is_even));
 
    std::cout << "\nPartitioned vector:\n    ";
    std::copy(v.begin(), v.end(), std::ostream_iterator<int>(std::cout, " "));
    std::cout << "\nBefore partition:\n    ";
    std::copy(v.begin(), p,       std::ostream_iterator<int>(std::cout, " "));
    std::cout << "\nAfter partition:\n    ";
    std::copy(p,         v.end(), std::ostream_iterator<int>(std::cout, " "));
}

Possible output:

Original vector:
    0 1 2 3 4 5 6 7 8 9 
Partitioned vector:
    0 8 2 6 4 5 3 7 1 9 
Before partition:
    0 8 2 6 4 
After partition:
    5 3 7 1 9

[editar] Veja também

determina se o intervalo é dividido pelo predicado dado
Original:
determines if the range is partitioned by the given predicate
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) [edit]
divide os elementos em dois grupos, preservando sua ordem relativa
Original:
divides elements into two groups while preserving their relative order
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) [edit]