mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-19 10:32:02 -05:00
72 lines
2.6 KiB
ReStructuredText
72 lines
2.6 KiB
ReStructuredText
|
.. Copyright David Abrahams 2006. Distributed under the Boost
|
||
|
|
.. Software License, Version 1.0. (See accompanying
|
||
|
|
.. file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
||
|
|
|
||
|
|
::
|
||
|
|
|
||
|
|
using namespace boost;
|
||
|
|
int i = 0;
|
||
|
|
|
||
|
|
typedef std::vector< int > element_range_type;
|
||
|
|
typedef std::list< int > index_type;
|
||
|
|
|
||
|
|
static const int element_range_size = 10;
|
||
|
|
static const int index_size = 4;
|
||
|
|
|
||
|
|
element_range_type elements( element_range_size );
|
||
|
|
for(element_range_type::iterator el_it = elements.begin() ; el_it != elements.end() ; ++el_it)
|
||
|
|
*el_it = std::distance(elements.begin(), el_it);
|
||
|
|
|
||
|
|
index_type indices( index_size );
|
||
|
|
for(index_type::iterator i_it = indices.begin() ; i_it != indices.end() ; ++i_it )
|
||
|
|
*i_it = element_range_size - index_size + std::distance(indices.begin(), i_it);
|
||
|
|
std::reverse( indices.begin(), indices.end() );
|
||
|
|
|
||
|
|
typedef permutation_iterator< element_range_type::iterator, index_type::iterator > permutation_type;
|
||
|
|
permutation_type begin = make_permutation_iterator( elements.begin(), indices.begin() );
|
||
|
|
permutation_type it = begin;
|
||
|
|
permutation_type end = make_permutation_iterator( elements.begin(), indices.end() );
|
||
|
|
|
||
|
|
std::cout << "The original range is : ";
|
||
|
|
std::copy( elements.begin(), elements.end(), std::ostream_iterator< int >( std::cout, " " ) );
|
||
|
|
std::cout << "\n";
|
||
|
|
|
||
|
|
std::cout << "The reindexing scheme is : ";
|
||
|
|
std::copy( indices.begin(), indices.end(), std::ostream_iterator< int >( std::cout, " " ) );
|
||
|
|
std::cout << "\n";
|
||
|
|
|
||
|
|
std::cout << "The permutated range is : ";
|
||
|
|
std::copy( begin, end, std::ostream_iterator< int >( std::cout, " " ) );
|
||
|
|
std::cout << "\n";
|
||
|
|
|
||
|
|
std::cout << "Elements at even indices in the permutation : ";
|
||
|
|
it = begin;
|
||
|
|
for(i = 0; i < index_size / 2 ; ++i, it+=2 ) std::cout << *it << " ";
|
||
|
|
std::cout << "\n";
|
||
|
|
|
||
|
|
std::cout << "Permutation backwards : ";
|
||
|
|
it = begin + (index_size);
|
||
|
|
assert( it != begin );
|
||
|
|
for( ; it-- != begin ; ) std::cout << *it << " ";
|
||
|
|
std::cout << "\n";
|
||
|
|
|
||
|
|
std::cout << "Iterate backward with stride 2 : ";
|
||
|
|
it = begin + (index_size - 1);
|
||
|
|
for(i = 0 ; i < index_size / 2 ; ++i, it-=2 ) std::cout << *it << " ";
|
||
|
|
std::cout << "\n";
|
||
|
|
|
||
|
|
|
||
|
|
The output is::
|
||
|
|
|
||
|
|
The original range is : 0 1 2 3 4 5 6 7 8 9
|
||
|
|
The reindexing scheme is : 9 8 7 6
|
||
|
|
The permutated range is : 9 8 7 6
|
||
|
|
Elements at even indices in the permutation : 9 7
|
||
|
|
Permutation backwards : 6 7 8 9
|
||
|
|
Iterate backward with stride 2 : 6 8
|
||
|
|
|
||
|
|
|
||
|
|
The source code for this example can be found `here`__.
|
||
|
|
|
||
|
|
__ ../example/permutation_iter_example.cpp
|