std::is_permutation

 

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 ForwardIt1, class ForwardIt2 > bool is_permutation( ForwardIt1 first, ForwardIt1 last,                      ForwardIt2 d_first );	(1)	(dal C++11)
template< class ForwardIt1, class ForwardIt2, class BinaryPredicate > bool is_permutation( ForwardIt1 first, ForwardIt1 last,                      ForwardIt2 d_first, BinaryPredicate p );	(2)	(dal C++11)

Ritorna true se esiste una permutazione degli elementi della [first1, last1) gamma che rende tale intervallo uguale all'inizio gamma a d_first. La prima versione utilizza operator== per l'uguaglianza, la seconda versione utilizza il p binario predicato

Original:

Returns true if there exists a permutation of the elements in the range [first1, last1) that makes that range equal to the range beginning at d_first. The first version uses operator== for equality, the second version uses the binary predicate p

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

Parametri

first, last	-	la gamma di elementi da confrontare Original: the range of 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.
d_first	-	all'inizio del secondo intervallo da confrontare Original: the beginning of the second range 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 ForwardIt1 and ForwardIt2 can be dereferenced and then implicitly converted to  Type1 and  Type2 respectively. ​
Type requirements
- ForwardIt1, ForwardIt2 must meet the requirements of ForwardIterator.

Valore di ritorno

true se il [first, last) intervallo è una permutazione di inizio gamma a d_first.

Original:

true if the range [first, last) is a permutation of the range beginning at d_first.

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

Complessità

Alla maggior parte delle applicazioni O(N²) del predicato, o esattamente N se le sequenze sono già uguali, N=std::distance(first, last) dove.

Original:

At most O(N²) applications of the predicate, or exactly N if the sequences are already equal, where N=std::distance(first, last).

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

Possibile implementazione

template<class ForwardIt1, class ForwardIt2> bool is_permutation(ForwardIt1 first, ForwardIt1 last, ForwardIt2 d_first) { // skip common prefix std::tie(first, d_first) = std::mismatch(first, last, d_first); // iterate over the rest, counting how many times each element // from [first, last) appears in [d_first, d_last) if (first != last) { ForwardIt2 d_last = d_first; std::advance(d_last, std::distance(first, last)); for (ForwardIt1 i = first; i != last; ++i) { if (i != std::find(first, i, *i)) continue; // already counted this *i   auto m = std::count(d_first, d_last, *i); if (m==0 || std::count(i, last, *i) != m) { return false; } } } return true; }

Esempio

#include <algorithm>
#include <vector>
#include <iostream>
int main()
{
    std::vector<int> v1{1,2,3,4,5};
    std::vector<int> v2{3,5,4,1,2};
    std::cout << "3,5,4,1,2 is a permutation of 1,2,3,4,5? "
              << std::boolalpha
              << std::is_permutation(v1.begin(), v1.end(), v2.begin()) << '\n';
 
    std::vector<int> v3{3,5,4,1,1};
    std::cout << "3,5,4,1,1 is a permutation of 1,2,3,4,5? "
              << std::boolalpha
              << std::is_permutation(v1.begin(), v1.end(), v3.begin()) << '\n';
}

Output:

3,5,4,1,2 is a permutation of 1,2,3,4,5? true
3,5,4,1,1 is a permutation of 1,2,3,4,5? false

Vedi anche

next_permutation	generates the next greater lexicographic permutation of a range of elements (funzione di modello)
prev_permutation	generates the next smaller lexicographic permutation of a range of elements (funzione di modello)