std::experimental::ranges::is_permutation

 

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Non-modifying sequence operations
all_ofany_ofnone_of countcount_if	findfind_iffind_if_not find_end find_first_of	adjacent_find search search_n mismatch	equal for_each lexicographical_compare
Modifying sequence operations
copycopy_if copy_n copy_backward move move_backward	fill fill_n generate generate_n swap_ranges shuffle transform	removeremove_if replacereplace_if reverse rotate unique	remove_copyremove_copy_if replace_copyreplace_copy_if reverse_copy rotate_copy unique_copy
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is_partitioned partition_point	partition partition_copy	stable_partition
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is_sorted is_sorted_until	sort stable_sort	partial_sort partial_sort_copy	nth_element
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lower_bound	upper_bound	binary_search	equal_range
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merge inplace_merge	includes	set_difference set_intersection	set_symmetric_difference set_union
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is_heap is_heap_until	make_heap sort_heap	push_heap pop_heap
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max max_element	min min_element	minmax minmax_element
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is_permutation	next_permutation	prev_permutation

 

Defined in header <experimental/ranges/algorithm>
template< ForwardIterator I1, Sentinel<I1> S1, ForwardIterator I2, Sentinel<I2> S2,           class Pred = ranges::equal_to<>,           class Proj1 = ranges::identity, class Proj2 = ranges::identity >   requires IndirectlyComparable<I1, I2, Pred, Proj1, Proj2> bool is_permutation(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = Pred{},                     Proj1 proj1 = Proj1{}, Proj2 proj2 = Proj2{});	(1)	(ranges TS)
template< ForwardRange R1, ForwardRange R2, class Pred = ranges::equal_to<>,           class Proj1 = ranges::identity, class Proj2 = ranges::identity >   requires IndirectlyComparable<ranges::iterator_t<R1>, ranges::iterator_t<R2>,                                 Pred, Proj1, Proj2> bool is_permutation(R1&& r1, R2&& r2, Pred pred = Pred{},                     Proj1 proj1 = Proj1{}, Proj2 proj2 = Proj2{});	(2)	(ranges TS)
template< ForwardIterator I1, Sentinel<I1> S1, class I2,           class Pred = ranges::equal_to<>,           class Proj1 = ranges::identity, class Proj2 = ranges::identity >   requires ForwardIterator<std::decay_t<I2>> && !Range<I2> &&            IndirectlyComparable<I1, std::decay_t<I2>, Pred, Proj1, Proj2> bool is_permutation(I1 first1, S1 last1, I2&& first2_, Pred pred = Pred{},                     Proj1 proj1 = Proj1{}, Proj2 proj2 = Proj2{});	(3)	(ranges TS) (deprecated)
template< ForwardRange R1, class I2, class Pred = ranges::equal_to<>,           class Proj1 = ranges::identity, class Proj2 = ranges::identity >   requires ForwardIterator<std::decay_t<I2>> && !Range<I2> &&            IndirectlyComparable<ranges::iterator_t<R1>, std::decay_t<I2>, Pred, Proj1, Proj2> bool is_permutation(R1&& r1, I2&& first2_, Pred pred = Pred{},                     Proj1 proj1 = Proj1{}, Proj2 proj2 = Proj2{});	(4)	(ranges TS) (deprecated)

1) Returns true if there exists a permutation of the elements in range [first1, last1) that makes the range equal to [first2, last2), and false otherwise.

2) Same as (1), but uses r1 as the first source range and r2 as the second source range, as if using ranges::begin(r1) as first1, ranges::end(r1) as last1, ranges::begin(r2) as first2, and ranges::end(r2) as last2.

3) Same as (1), except that first2 is defined as if by std::decay_t<I2> first2 = std::forward<I2>(first2_); and last2 is first2 + (last1 - first1).

4) Same as (3), but uses r1 as the first source range, as if using ranges::begin(r1) as first1 and ranges::end(r1) as last1.

Two ranges are considered equal if they have the same number of elements and, for every iterator i in the range [first1, last1), ranges::invoke(pred, ranges::invoke(proj1, *i), ranges::invoke(proj2, *(first2 + (i - first1)))) is true.

Notwithstanding the declarations depicted above, the actual number and order of template parameters for algorithm declarations is unspecified. Thus, if explicit template arguments are used when calling an algorithm, the program is probably non-portable.

Parameters

first1, last1	-	the first range of the elements
r1	-	the first range of the elements
first2, last2	-	the second range of the elements
r2	-	the second range of the elements
first2_	-	the beginning of the second range of the elements
pred	-	predicate to apply to the projected elements
proj1	-	projection to apply to the elements in the first range
proj2	-	projection to apply to the elements in the second range

Return value

true if the range [first1, last1) is a permutation of the range [first2, last2).

Complexity

At most O(N²) applications of the predicate and each projection, or exactly N if the sequences are already equal, where N=last1 - first1).

However if SizedSentinel<S1, I1> && SizedSentinel<S2, I2> is satisfied and last1 - first1 != last2 - first2, no applications of the predicate and projections are made.

See also

is_permutation (C++11)	determines if a sequence is a permutation of another sequence (function template)
next_permutation	generates the next greater lexicographic permutation of a range of elements (function template)
prev_permutation	generates the next smaller lexicographic permutation of a range of elements (function template)