std::bsearch
Da cppreference.com.
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Defined in header <cstdlib> | ||
void* bsearch(constvoid* key, constvoid* ptr, size_t count, size_t size, int(*comp)(constvoid*, constvoid*)); | ||
Trova un elemento pari a elemento puntato da
key
in un array puntato da ptr
. La matrice contiene elementi count
di size
dimensioni. Funzione puntato da comp
viene utilizzato per confronto oggetto.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.
Indice |
[modifica]Parametri
key | - | puntatore all'elemento da ricercare 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 | - | puntatore alla matrice da esaminare 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 | - | numero di elemento della matrice 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 | - | dimensione di ciascun elemento della matrice in byte 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. int cmp(constvoid*a, constvoid*b); The function must not modify the objects passed to it. |
[modifica]Valore di ritorno
Puntatore all'elemento trovato o NULL altrimenti.
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.
[modifica]Esempio
#include <cstdlib>#include <iostream> int compare(constvoid*ap, constvoid*bp){constint*a =(int*) ap;constint*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){constint 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);}
Output:
p1: 0xbf9a4c88 4 p2: NULL
[modifica]Vedi anche
Ordina un intervallo di elementi di tipo non specificato Original: sorts a range of elements with unspecified type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (funzione) | |
torna gamma di elementi che corrispondono un tasto specifico 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. (funzione di modello) | |
C documentation for bsearch |