std::adjacent_difference
De cppreference.com
 |
This page has been machine-translated from the English version of the wiki using Google Translate.
The translation may contain errors and awkward wording. Hover over text to see the original version. You can help to fix errors and improve the translation. For instructions click here. |
<metanoindex/>
<tbody> </tbody>| Déclaré dans l'en-tête <numeric>
|
||
template< class InputIt, class OutputIt > OutputIt adjacent_difference( InputIt first, InputIt last, OutputIt d_first ); |
(1) | |
template< class InputIt, class OutputIt, class BinaryOperation > OutputIt adjacent_difference( InputIt first, InputIt last, OutputIt d_first, BinaryOperation op ); |
(2) | |
Calcule les différences entre la deuxième et la première de chaque paire adjacente d'éléments de la gamme
[first, last) et les écrit dans la gamme de début d_first + 1. Copie non modifiée de first est écrit d_first. La première version utilise operator- de calculer les différences, la deuxième version utilise la fonction binaire donné op .Original:
Computes the differences between the second and the first of each adjacent pair of elements of the range
[first, last) and writes them to the range beginning at d_first + 1. Unmodified copy of first is written to d_first. The first version uses operator- to calculate the differences, 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.
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.
You can help to correct and verify the translation. Click here for instructions.
*(d_first) = *first;
*(d_first+1) = (*first+1) - *(first);
*(d_first+2) = (*first+2) - *(first+1);
*(d_first+3) = (*first+3) - *(first+2);
...
Paramètres
| first, last | - | la plage d'éléments
Original: the 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. |
| 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:
The signature does not need to have |
| Type requirements | ||
-InputIt must meet the requirements of InputIterator.
| ||
-OutputIt must meet the requirements of OutputIterator.
| ||
Retourne la valeur
Il à l'élément après le dernier élément écrit .
Original:
It 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.
You can help to correct and verify the translation. Click here for instructions.
Complexité
Exactement
(last - first) - 1 applications de l'opération binaireOriginal:
Exactly
(last - first) - 1 applications of the binary operationThe 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.
Mise en œuvre possible
| First version |
|---|
template<class InputIt, class OutputIt>
OutputIt adjacent_difference(InputIt first, InputIt last,
OutputIt d_first)
{
if (first == last) return d_first;
typedef typename std::iterator_traits<InputIt>::value_type value_t;
value_t acc = *first;
*d_first = acc;
while (++first != last) {
value_t val = *first;
*++d_first = val - acc;
acc = std::move(val);
}
return ++d_first;
}
|
| Second version |
template<class InputIt, class T, class BinaryOperation>
OutputIt adjacent_difference(InputIt first, InputIt last,
OutputIt d_first, BinaryOperation op)
{
if (first == last) return d_first;
typedef typename std::iterator_traits<InputIt>::value_type value_t;
value_t acc = *first;
*d_first = acc;
while (++first != last) {
value_t val = *first;
*++d_first = op(val, acc);
acc = std::move(val);
}
return ++d_first;
}
|
Exemple
Le code suivant convertit une séquence de nombres pairs de répétitions du numéro 2 et convertit une séquence de celles d'une séquence de nombres de Fibonacci .
Original:
The following code converts a sequence of even numbers to repetitions of the number 2 and converts a sequence of ones to a sequence of Fibonacci numbers.
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.
#include <numeric>
#include <vector>
#include <iostream>
#include <functional>
int main()
{
std::vector<int> v{2, 4, 6, 8, 10, 12, 14, 16, 18, 20};
std::adjacent_difference(v.begin(), v.end(), v.begin());
for(auto n: v) {
std::cout << n << ' ';
}
std::cout << '\n';
v = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1};
std::adjacent_difference(v.begin(), v.end()-1, v.begin()+1, std::plus<int>()
for(auto n: v) {
std::cout << n << ' ';
}
std::cout << '\n';
}
Résultat :
2 2 2 2 2 2 2 2 2 2
1 1 2 3 5 8 13 21 34 55
Voir aussi
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) | |
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) | |