std::set_difference
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<metanoindex/>
<tbody> </tbody>| Déclaré dans l'en-tête <algorithm>
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template< class InputIt1, class InputIt2, class OutputIt > OutputIt set_difference( InputIt1 first1, InputIt1 last1, InputIt2 first2, InputIt2 last2, OutputIt d_first ); |
(1) | |
template< class InputIt1, class InputIt2, class OutputIt, class Compare > OutputIt set_difference( InputIt1 first1, InputIt1 last1, InputIt2 first2, InputIt2 last2, OutputIt d_first, Compare comp ); |
(2) | |
Copie les éléments de la gamme
[first1, last1) triés qui ne se trouvent pas dans la gamme triés [first2, last2) au début de la plage à d_first . Original:
Copies the elements from the sorted range
[first1, last1) which are not found in the sorted range [first2, last2) to the range beginning at d_first. The text has been machine-translated via Google Translate.
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La plage résultante est également triée. La première version prévoit à la fois d'entrée se situe à trier avec
operator<, la deuxième version s'attend à ce qu'ils soient triés à la comp fonction de comparaison donnée. éléments équivalents sont traités individuellement , qui est, si un élément est trouvé m fois dans [first1, last1) et n fois dans [first2, last2), il sera copié dans d_first exactement std::max(m-n, 0) fois. La gamme résultante ne peut pas faire double emploi avec l'une des plages d'entrée .Original:
The resulting range is also sorted. The first version expects both input ranges to be sorted with
operator<, the second version expects them to be sorted with the given comparison function comp. Equivalent elements are treated individually, that is, if some element is found m times in [first1, last1) and n times in [first2, last2), it will be copied to d_first exactly std::max(m-n, 0) times. The resulting range cannot overlap with either of the input ranges.The text has been machine-translated via Google Translate.
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Paramètres
| first1, last1 | - | l'éventail des éléments à examiner
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. |
| first2, last2 | - | l'éventail des éléments à rechercher
Original: the range of elements to search for 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:
The signature does not need to have |
| Type requirements | ||
-InputIt1 must meet the requirements of InputIterator.
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-InputIt2 must meet the requirements of InputIterator.
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-OutputIt must meet the requirements of OutputIterator.
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Retourne la valeur
Iterator-delà de la fin de la gamme construit .
Original:
Iterator past the end of the constructed range.
The text has been machine-translated via Google Translate.
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Complexité
A comparaisons plupart 2·(N1+N2-1), où N1
= std::distance(first1, last1) et N2 = std::distance(first2, last2) .Original:
At most 2·(N1+N2-1) comparisons, where N1
= std::distance(first1, last1) and N2 = std::distance(first2, last2).The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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Mise en œuvre possible
| First version |
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template<class InputIt1, class InputIt2, class OutputIt>
OutputIt set_difference(InputIt1 first1, InputIt1 last1,
InputIt2 first2, InputIt2 last2,
OutputIt d_first)
{
while (first1 != last1) {
if (first2 == last2) return std::copy(first1, last1, d_first);
if (*first1 < *first2) {
*d_first++ = *first1++;
} else {
if (! (*first2 < *first1)) {
++first1;
}
++first2;
}
}
return d_first;
}
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| Second version |
template<class InputIt1, class InputIt2,
class OutputIt, class Compare>
OutputIt set_difference( InputIt1 first1, InputIt1 last1,
InputIt2 first2, InputIt2 last2,
OutputIt d_first, Compare comp)
{
while (first1 != last1) {
if (first2 == last2) return std::copy(first1, last1, d_first);
if (comp(*first1, *first2)) {
*d_first++ = *first1++;
} else {
if (!comp(*first2, *first1)) {
++first1;
}
++first2;
}
}
return d_first;
}
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Exemple
#include <iostream>
#include <algorithm>
#include <vector>
#include <iterator>
int main() {
std::vector<int> v1 {1, 2, 5, 5, 5, 9};
std::vector<int> v2 {2, 5, 7};
std::vector<int> diff;
std::set_difference(v1.begin(), v1.end(), v2.begin(), v2.end(),
std::inserter(diff, diff.begin()));
for (auto i : v1) std::cout << i << ' ';
std::cout << "minus ";
for (auto i : v2) std::cout << i << ' ';
std::cout << "is: ";
for (auto i : diff) std::cout << i << ' ';
std::cout << '\n';
}
Résultat :
1 2 5 5 5 9 minus 2 5 7 is: 1 5 5 9
Voir aussi
retourne vrai si un ensemble est un sous-ensemble de l'autre Original: returns true if one set is a subset of another 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 différence symétrique entre deux ensembles Original: computes the symmetric difference between two sets The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (fonction générique) | |