std::equal

 

C++

Linguaggio

Concetti

Libreria di Utilità

Stringhe

Contenitori

Algoritmi

Iteratori

Libreria matematca

Input/output

Localizzazione

Espressioni regolari(C++11)

Operazioni atomicche(C++11)

Multithreading(C++11)

 

Algoritmo libreria

Funzioni Original: Functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
Non modifica le operazioni di sequenza Original: Non-modifying sequence operations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
all_of any_of none_of (C++11) (C++11) (C++11) for_each count count_if mismatch equal	find find_if find_if_not (C++11) find_end find_first_of adjacent_find search search_n
Modifica delle operazioni di sequenza Original: Modifying sequence operations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
copy copy_if (C++11) copy_n (C++11) copy_backward move (C++11) move_backward (C++11) fill fill_n transform generate generate_n remove remove_if remove_copy remove_copy_if	replace replace_if replace_copy replace_copy_if swap swap_ranges iter_swap reverse reverse_copy rotate rotate_copy random_shuffle shuffle   (C++11) unique unique_copy
Partizionamento operazioni Original: Partitioning operations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
is_partitioned (C++11) partition partition_copy (C++11)	stable_partition partition_point (C++11)
Ordinamento delle operazioni (su intervalli ordinati) Original: Sorting operations (on sorted ranges) The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
is_sorted (C++11) is_sorted_until (C++11) sort	partial_sort partial_sort_copy stable_sort nth_element
Binarie (le operazioni di ricerca sui campi ordinati) Original: Binary search operations (on sorted ranges) The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
lower_bound upper_bound	binary_search equal_range
Impostare le operazioni (su intervalli ordinati) Original: Set operations (on sorted ranges) The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
merge inplace_merge includes	set_difference set_intersection set_symmetric_difference set_union
Heap operazioni Original: Heap operations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
is_heap is_heap_until (C++11) make_heap	push_heap pop_heap sort_heap
Minimo / massimo le operazioni Original: Minimum/maximum operations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
max max_element min min_element minmax (C++11) minmax_element (C++11)	lexicographical_compare is_permutation (C++11) next_permutation prev_permutation
Operazioni numeriche Original: Numeric operations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
iota (C++11) accumulate inner_product	adjacent_difference partial_sum
Libreria C Original: C library The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
qsort	bsearch

 

Defined in header <algorithm>
template<class InputIt1, class InputIt2 > bool equal( InputIt1 first1, InputIt1 last1,             InputIt2 first2 );	(1)
template<class InputIt1, class InputIt2, class BinaryPredicate > bool equal( InputIt1 first1, InputIt1 last1,             InputIt2 first2, BinaryPredicate p );	(2)

Restituisce true se gli elementi sono gli stessi in due gruppi: uno definito da [first1, last1) e un altro a partire da first2. La prima versione della funzione utilizza operator== per confrontare gli elementi, il secondo utilizza il predicato binario dato p.

Original:

Returns true if the elements are the same in two ranges: one defined by [first1, last1) and another starting at first2. The first version of the function uses operator== to compare the elements, the second uses the given binary predicate p.

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Parametri

first1, last1	-	la prima gamma di elementi da confrontare Original: the first range of the elements to compare The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
first2	-	all'inizio del secondo intervallo di elementi da confrontare Original: beginning of the second range of the elements to compare The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
p	-	binary predicate which returns ​true if the elements should be treated as equal. The signature of the predicate function should be equivalent to the following:  bool pred(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 types  Type1 and  Type2 must be such that objects of types InputIt1 and InputIt2 can be dereferenced and then implicitly converted to  Type1 and  Type2 respectively. ​
Type requirements
- InputIt1, InputIt2 must meet the requirements of InputIterator.

Valore di ritorno

true se gli elementi delle due gamme sono uguali

Original:

true if the elements in the two ranges are equal

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Note

std::equal non può essere utilizzata per confrontare gli intervalli formate dagli iteratori da std::unordered_set, std::unordered_multiset, std::unordered_map o std::unordered_multimap perché l'ordine in cui sono memorizzati gli elementi in tali contenitori possono essere diversi, anche se i due contenitori memorizzare gli stessi elementi.

Original:

std::equal may not be used to compare the ranges formed by the iterators from std::unordered_set, std::unordered_multiset, std::unordered_map, or std::unordered_multimap because the order in which the elements are stored in those containers may be different even if the two containers store the same elements.

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{{{1}}}

Original:

{{{2}}}

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Complessità

Al massimo last1 - first1 applicazioni del predicato

Original:

At most last1 - first1 applications of the predicate

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Possibile implementazione

First version
template<class InputIt1, class InputIt2>bool equal(InputIt1 first1, InputIt1 last1, InputIt2 first2){for(; first1 != last1;++first1, ++first2){if(!(*first1 ==*first2)){returnfalse;}}returntrue;}
Second version
template<class InputIt1, class InputIt2, class BinaryPredicate>bool equal(InputIt1 first1, InputIt1 last1, InputIt2 first2, BinaryPredicate p){for(; first1 != last1;++first1, ++first2){if(!p(*first1, *first2)){returnfalse;}}returntrue;}

Esempio

Il codice seguente utilizza equal() per verificare se una stringa è un palindromo

Original:

The following code uses equal() to test if a string is a palindrome

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#include <iostream>#include <algorithm>#include <string>   void test(conststd::string& s){if(std::equal(s.begin(), s.begin()+ s.size()/2, s.rbegin())){std::cout<<"\""<< s <<"\" is a palindrome\n";}else{std::cout<<"\""<< s <<"\" is not palindrome\n";}}int main(){ test("radar"); test("hello");}

Output:

"radar" is a palindrome "hello" is not palindrome

find find_if find_if_not (C++11)	trova il primo elemento che soddisfi i criteri specifici Original: finds the first element satisfying specific criteria 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)
lexicographical_compare	restituisce true se un intervallo è lessicograficamente minore di un altro Original: returns true if one range is lexicographically less than another 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)
mismatch	trova la prima posizione in cui due intervalli diversi Original: finds the first position where two ranges differ 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)
search	searches for a range of elements (funzione di modello)