std::binary_search

 

C++

Lenguaje

Cabeceras

Conceptos

Biblioteca de utilidades

Biblioteca de cadenas

Biblioteca de contenedores

Biblioteca de algoritmos

Biblioteca de iteradores

Biblioteca numérica

Biblioteca de entrada/salida

Biblioteca de localización

Biblioteca de expresiones regulares(C++11)

Biblioteca de operaciones atómicas(C++11)

Biblioteca de hilos/subprocesos(C++11)

 

Biblioteca de algoritmos

Políticas de ejecución (C++17)
is_execution_policy	execution::seqexecution::parexecution::par_unseq	execution::sequenced_policyexecution::parallel_policyexecution::parallel_unsequenced_policy
Operaciones no modificadoras de secuencia
all_ofany_ofnone_of (C++11)(C++11)(C++11) for_each for_each_n (C++17)	countcount_if mismatch equal adjacent_find	findfind_iffind_if_not (C++11) find_end find_first_of	search search_n lexicographical_compare lexicographical_compare_3way (C++20)
Operaciones modificadoras de secuencia
copycopy_if (C++11) copy_n (C++11) copy_backward move (C++11) move_backward (C++11) transform	fill fill_n generate generate_n swap iter_swap swap_ranges sample (C++17)	removeremove_if replacereplace_if reverse rotate unique random_shuffle (hasta C++17)	remove_copyremove_copy_if replace_copyreplace_copy_if reverse_copy rotate_copy unique_copy shuffle (C++11)
Operaciones en almacenamiento no inicializado
uninitialized_copy uninitialized_move (C++17)	uninitialized_copy_n (C++11) uninitialized_move_n (C++17)	uninitialized_fill	uninitialized_fill_n
Operaciones de partición
is_partitioned (C++11) partition_point (C++11)	partition partition_copy (C++11)	stable_partition
Operaciones de ordenación
is_sorted (C++11) is_sorted_until (C++11)	sort stable_sort	partial_sort partial_sort_copy	nth_element
Operaciones de búsqueda binaria
lower_bound	upper_bound	binary_search	equal_range
Operaciones de set (en rangos ordenados)
merge inplace_merge	set_difference set_intersection	set_symmetric_difference set_union	includes
Operaciones de pila
is_heap (C++11) is_heap_until (C++11)	make_heap sort_heap	push_heap pop_heap
Operaciones minimo/maximo
max max_element	min min_element	minmax (C++11) minmax_element (C++11)	clamp (C++17) compare_3way (C++20)
Permutaciones
is_permutation (C++11)	next_permutation	prev_permutation
Operaciones numéricas
iota (C++11) inner_product adjacent_difference	accumulate reduce (C++17) transform_reduce (C++17)	partial_sum inclusive_scan (C++17) exclusive_scan (C++17)	transform_inclusive_scan (C++17) transform_exclusive_scan (C++17)
Bibliotecas C
qsort	bsearch

 

Definido en la cabecera <algorithm>
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)

Comprueba si el rango [first, last) ordenados contiene un elemento igual a value. La primera versión utiliza operator< para comparar los elementos, la segunda versión utiliza la función de comparación dado 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.

Parámetros

first, last	-	la gama de elementos a examinar 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	-	valor para comparar los elementos a 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. The type Type1 must be such that an object of type T can be implicitly converted to Type1. The type Type2 must be such that an object of type ForwardIt can be dereferenced and then implicitly converted to Type2. ​
Requerimientos de tipo
- ForwardIt debe reunir los requerimientos de ForwardIterator.

Valor de retorno

true si un elemento igual a value se encuentra, por lo demás false .

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.

Complejidad

Logarítmica en la distancia entre first y last

Original:

Logarithmic in the distance between first and last

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

Posible implementación

Primera versión
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));}
Segunda versión
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));}

Ejemplo

#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";}}}

Salida:

Searching for 1 Found 1 Searching for 2 no dice! Searching for 3 Found 3

Ver también

equal_range

El rendimiento es de los elementos que coinciden con una clave específica 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. (plantilla de función)