BitMagic-C++
svsample03.cpp

Example of how to merge sparse vectors and extract values fast

See also
bm::sparse_vector<>::set
bm::sparse_vector<>::import
bm::sparse_vector<>::decode
bm::sparse_vector<>::join
/*
Copyright(c) 2002-2017 Anatoliy Kuznetsov(anatoliy_kuznetsov at yahoo.com)
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
For more information please visit: http://bitmagic.io
*/
/** \example svsample03.cpp
Example of how to merge sparse vectors and extract values fast
\sa bm::sparse_vector<>::set
\sa bm::sparse_vector<>::import
\sa bm::sparse_vector<>::decode
\sa bm::sparse_vector<>::join
*/
/*! \file svsample03.cpp
\brief Example: sparse_vector<> merge and fast extraction of content
*/
#include <iostream>
#include <vector>
#include "bm.h"
#include "bmsparsevec.h"
using namespace std;
int main(void)
{
unsigned i;
unsigned arr[3] = {1,2,3};
sv1.import(arr, 3); // import from a C-style array (fastest way to populate)
// optimize memory allocation of sparse vector
{
sv1.optimize(tb);
}
cout << "sv1.size() = " << sv1.size() << ": ";
for (i = 0; i < sv1.size(); ++i)
{
cout << sv1.at(i) << ",";
}
cout << endl;
// populate second sparse vector using dunamic resize assignment
//
for (i = 65536; i < 65536+10; ++i)
{
sv2.set(i, 256+i);
}
cout << "sv2.size() = " << sv2.size() << endl;
cout << "Perform sparse_vector<>::join()" << endl;
// join sv2 into sv1
// operation implemented using bitset OR on all bit-planes.
sv1.join(sv2);
sv1.optimize(); // please note, we use default optimize here (it is a bit slower)
cout << "Now sv1.size() = " << sv1.size() << endl;
std::vector<unsigned> v1(16);
sv1.decode(&v1[0], 65530, 16); // extract 16 elements starting from 65530
for (i = 0; i < 16; ++i)
{
cout << v1[i] << ",";
}
cout << endl;
return 0;
}
bm::sparse_vector::optimize
void optimize(bm::word_t *temp_block=0, typename bvector_type::optmode opt_mode=bvector_type::opt_compress, typename sparse_vector< Val, BV >::statistics *stat=0)
run memory optimization for all vector plains
Definition: bmsparsevec.h:1750
bm::sparse_vector
sparse vector with runtime compression using bit transposition method
Definition: bmsparsevec.h:81
BM_DECLARE_TEMP_BLOCK
#define BM_DECLARE_TEMP_BLOCK(x)
Definition: bm.h:47
bmsparsevec.h
Sparse constainer sparse_vector<> for integer types using bit-transposition transform.
bm::sparse_vector::import
void import(const value_type *arr, size_type arr_size, size_type offset=0, bool set_not_null=true)
Import list of elements from a C-style array.
Definition: bmsparsevec.h:1000
bm::sparse_vector::size
size_type size() const BMNOEXCEPT
return size of the vector
Definition: bmsparsevec.h:644
main
int main(void)
Definition: svsample03.cpp:40
bm::sparse_vector::at
value_type at(size_type idx) const
access specified element with bounds checking
Definition: bmsparsevec.h:1440
bm::sparse_vector::decode
size_type decode(value_type *arr, size_type idx_from, size_type dec_size, bool zero_mem=true) const
Bulk export list of elements to a C-style array.
Definition: bmsparsevec.h:1089
bm::sparse_vector::join
sparse_vector< Val, BV > & join(const sparse_vector< Val, BV > &sv)
join all with another sparse vector using OR operation
Definition: bmsparsevec.h:1786
bm.h
Compressed bit-vector bvector<> container, set algebraic methods, traversal iterators.
bm::sparse_vector::set
void set(size_type idx, value_type v)
set specified element with bounds checking and automatic resize
Definition: bmsparsevec.h:1475