Espaces de noms
Variantes
Affichages
Actions

std::partial_sum

De cppreference.com
< cpp‎ | algorithm

 
 
Bibliothèque d'algorithmes
Fonctions
Original:
Functions
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Non-modification de la séquence des opérations
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.
Modification de la séquence des opérations
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.
Des opérations de partitionnement
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.
Opérations de tri (sur les gammes triés)
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.
is_sorted (C++11)
is_sorted_until (C++11)
sort
Opérations binaires de recherche (sur les gammes triés)
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.
Définir les opérations (sur les gammes triés)
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.
Opérations Heap
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.
Minimum / maximum de fonctionnement
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.
Opérations numériques
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.
adjacent_difference
partial_sum
Bibliothèque C
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 <numeric>
template< class InputIt, class OutputIt >
OutputIt partial_sum( InputIt first, InputIt last, OutputIt d_first );
(1)
template< class InputIt, class OutputIt, class BinaryOperation >

OutputIt partial_sum( InputIt first, InputIt last, OutputIt d_first,

                      BinaryOperation op );
(2)
Calcule les sommes partielles des éléments de la sous-gammes de [first, last) gamme et les écrit dans le début de la plage à d_first. La première version utilise operator+ de résumer les éléments, la deuxième version utilise la fonction binaire donné op .
Original:
Computes the partial sums of the elements in the subranges of the range [first, last) and writes them to the range beginning at d_first. The first version uses operator+ to sum up the elements, the second version uses the given binary function op.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Opération équivalente:
Original:
Equivalent operation:
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
*(d_first)   = *first;
*(d_first+1) = *first + *(first+1);
*(d_first+2) = *first + *(first+1) + *(first+2);
*(d_first+3) = *first + *(first+1) + *(first+2) + *(first+3);
...

Sommaire

[modifier] Paramètres

first, last -
la gamme des éléments de somme
Original:
the range of elements to sum
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
d_first -
le début de la plage de destination
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.
op - binary operation function object that will be applied.

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

 Ret fun(const Type1 &a, const Type2 &b);

The signature does not need to have const &.
The type  Type1 must be such that an object of type iterator_traits<InputIt>::value_type can be implicitly converted to  Type1. The type  Type2 must be such that an object of type InputIt can be dereferenced and then implicitly converted to  Type2. The type  Ret must be such that an object of type iterator_traits<InputIt>::value_type can be assigned a value of type  Ret. ​

Type requirements
-
InputIt must meet the requirements of InputIterator.
-
OutputIt must meet the requirements of OutputIterator.

[modifier] Retourne la valeur

Itérateur à l'élément après le dernier élément écrit .
Original:
Iterator to the element past the last element written.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[modifier] Complexité

Exactement (last - first) - 1 applications de l'opération binaire
Original:
Exactly (last - first) - 1 applications of the binary operation
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[modifier] Mise en œuvre possible

First version
template<class InputIt, class OutputIt>
OutputIt partial_sum(InputIt first, InputIt last, 
                           OutputIt d_first)
{
    return std::partial_sum(first, last, d_first, 
                            std::plus<InputIt, InputIt>());
}
Second version
template<class InputIt, class OutputIt, class BinaryOperator>
OutputIt partial_sum(InputIt first, InputIt last, 
                           OutputIt d_first, BinaryOperation op)
{
    if (first == last) return d_first;
 
    typename std::iterator_traits<InputIt>::value_type sum = *first;
    *d_first = sum;
 
    while (++first != last) {
       sum = op(sum, *first);
       *++d_first = sum;
    }
    return ++d_first;
}

[modifier] Exemple

#include <numeric>
#include <vector>
#include <iostream>
#include <iterator>
#include <functional>
int main()
{
    std::vector<int> v = {2,2,2,2,2,2,2,2,2,2};
 
    std::cout << "The first 10 even numbers are: ";
    std::partial_sum(v.begin(), v.end(), 
                     std::ostream_iterator<int>(std::cout, " "));
    std::cout << '\n';
 
    std::partial_sum(v.begin(), v.end(), v.begin(), std::multiplies<int>());
    std::cout << "The first 10 powers of 2 are: ";
    for(auto n: v) {
        std::cout << n << " ";
    }
    std::cout << '\n';
}

Résultat :

The first 10 even numbers are: 2 4 6 8 10 12 14 16 18 20 
The first 10 powers of 2 are: 2 4 8 16 32 64 128 256 512 1024

[modifier] Voir aussi

calcule les différences entre les éléments adjacents dans une gamme
Original:
computes the differences between adjacent elements in a range
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

(fonction générique) [edit]
résume un ensemble d'éléments
Original:
sums up a range of elements
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

(fonction générique) [edit]