std::bsearch
De cppreference.com
<metanoindex/>
<tbody> </tbody>| Definido no cabeçalho <cstdlib>
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void* bsearch( const void* key, const void* ptr, size_t count, size_t size, int (*comp)(const void*, const void*) ); |
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Localiza um elemento igual ao elemento apontado por
key em uma matriz apontada por ptr. A matriz contém elementos count de size tamanho. Função apontada pelo comp é usado para comparação de objetos.Original:
Finds an element equal to element pointed to by
key in an array pointed to by ptr. The array contains count elements of size size. Function pointed to by comp is used for object comparison.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.
Parâmetros
| key | - | ponteiro para o elemento para pesquisar
Original: pointer to the element 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. |
| ptr | - | ponteiro para a matriz para examinar
Original: pointer to the array to examine The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| count | - | número de elementos na matriz
Original: number of element in the array The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| size | - | tamanho de cada elemento na matriz em bytes
Original: size of each element in the array in bytes 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 a negative integer value if the first argument is less than the second, a positive integer value if the first argument is greater than the second and zero if the arguments are equal.
The function must not modify the objects passed to it. |
Valor de retorno
Ponteiro para o elemento encontrado ou NULL contrário.
Original:
Pointer to the found element or NULL 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.
Exemplo
#include <cstdlib>
#include <iostream>
int compare(const void *ap, const void *bp)
{
const int *a = (int *) ap;
const int *b = (int *) bp;
return *a - *b;
}
int show_ptr(int *p)
{
if (p == NULL) {
std::cout << "NULL\n";
} else {
std::cout << p1 << ' ' << *p1 << '\n';
}
}
int main(int argc, char **argv)
{
const int ARR_SIZE = 8;
int arr[ARR_SIZE] = { 1, 2, 3, 4, 5, 6, 7, 8 };
int key1 = 4;
int *p1 = (int *) std::bsearch(&key1, arr, ARR_SIZE, sizeof(arr[0]), compare);
int key2 = 9;
int *p2 = (int *) std::bsearch(&key2, arr, ARR_SIZE, sizeof(arr[0]), compare);
std::cout << "p1: ";
show_ptr(p1);
std::cout << "p2: ";
show_ptr(p2);
}
Saída:
p1: 0xbf9a4c88 4
p2: NULL