std::accumulate
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Déclaré dans l'en-tête <numeric> | ||
template<class InputIt, class T > T accumulate( InputIt first, InputIt last, T init ); | (1) | |
template<class InputIt, class T, class BinaryOperation > T accumulate( InputIt first, InputIt last, T init, | (2) | |
Calcule la somme de la valeur donnée
init et des éléments de [first, last). La première version utilise l' operator+ pour sommer les éléments. La deuxième version utilise la fonction binaire donnée op . Original:
Computes the sum of the given value
init and the elements in the range [first, last). 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.
You can help to correct and verify the translation. Click here for instructions.
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. |
| init | - | valeur initiale de la somme Original: initial value of the sum 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&. |
| Type requirements | ||
-InputIt must meet the requirements of InputIterator. | ||
-T must meet the requirements of CopyAssignable and CopyConstructible. | ||
[modifier]Retourne la valeur
La somme de la valeur donnée et des éléments dans la gamme proposée .
Original:
The sum of the given value and elements in the given range.
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.
[modifier]Mise en œuvre possible
| First version |
|---|
template<class InputIt, class T> T accumulate(InputIt first, InputIt last, T value){for(; first != last;++first){ value = value +*first;}return value;} |
| Second version |
template<class InputIt, class T, class BinaryOperation> T accumulate(InputIt first, InputIt last, T value, BinaryOperation op){for(; first != last;++first){ value = op(value, *first);}return value;} |
[modifier]Exemple
#include <iostream>#include <vector>#include <numeric>#include <string> int multiply(int x, int y){return x*y;} std::string magic_function(std::string res, int x){return res +=(x >5)?"b":"s";} int main(){std::vector<int> v{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; int sum = std::accumulate(v.begin(), v.end(), 0);int product = std::accumulate(v.begin(), v.end(), 1, multiply);std::string magic = std::accumulate(v.begin(), v.end(), std::string(), magic_function); std::cout<< sum <<'\n'<< product <<'\n'<< magic <<'\n';}
Résultat :
55 3628800 sssssbbbbb
[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) | |
calcule le produit scalaire de deux gammes d'éléments Original: computes the inner product of two ranges 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) | |
calcule la somme partielle d'une série d'éléments Original: computes the partial sum of 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) | |
