std::binary_search
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| Déclaré dans l'en-tête <algorithm>
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| template< class ForwardIt, class T > bool binary_search( ForwardIt first, ForwardIt last, const T& value ); |
(1) | |
| template< class ForwardIt, class T, class Compare > bool binary_search( ForwardIt first, ForwardIt last, const T& value, Compare comp ); |
(2) | |
Vérifie si le
[first, last) gamme triée contient un élément égal à value. La première version utilise operator< de comparer les éléments, la deuxième version utilise la fonction de comparaison donnée comp .Original:
Checks if the sorted range
[first, last) contains an element equal to value. The first version uses operator< to compare the elements, the second version uses the given comparison function comp.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 | - | 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. |
| value | - | valeur à comparer les éléments d'
Original: value to compare the elements to 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: bool cmp(const Type1 &a, const Type2 &b); The signature does not need to have const &, but the function must not modify the objects passed to it. |
| Type requirements | ||
-ForwardIt must meet the requirements of ForwardIterator.
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[modifier] Retourne la valeur
true si un élément égal à
value se trouve, false autrement .Original:
true if an element equal to
value is found, false otherwise.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] Complexité
Logarithmique de la distance entre
first et lastOriginal:
Logarithmic in the distance between
first and lastThe 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 |
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template<class ForwardIt, class T> bool binary_search(ForwardIt first, ForwardIt last, const T& value) { first = std::lower_bound(first, last, value); return (first != last && !(value < *first)); } |
| Second version |
template<class ForwardIt, class T, class Compare> bool binary_search(ForwardIt first, ForwardIt last, const T& value, Compare comp) { first = std::lower_bound(first, last, value); return (first != last && !(comp(value, *first)); } |
[modifier] Exemple
#include <iostream> #include <algorithm> #include <vector> int main() { std::vector<int> haystack {1, 3, 4, 5, 9}; std::vector<int> needles {1, 2, 3}; for (auto needle : needles) { std::cout << "Searching for " << needle << '\n'; if (std::binary_search(haystack.begin(), haystack.end(), needle)) { std::cout << "Found " << needle << '\n'; } else { std::cout << "no dice!\n"; } } }
Résultat :
Searching for 1 Found 1 Searching for 2 no dice! Searching for 3 Found 3
[modifier] Voir aussi
| rendements varient d'éléments correspondant à une clé spécifique Original: returns range of elements matching a specific key The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (fonction générique) | |
