BitMagic-C++
sample15.cpp

Example for finding first and last bits in bit-vector (dynamic range).

Example for finding first and last bits in bit-vector (dynamic range).Ranges of bit-vectors can be used to find probability of intersection. For instance, in some corner cases AND product can be predicted empty if vectors belong to different ranges.

@sa bm::bvector<>::find()
@sa bm::bvector<>::find_reverse()
@sa bm::bvector<>::find_range()
/*
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 sample15.cpp
Example for finding first and last bits in bit-vector (dynamic range).
Ranges of bit-vectors can be used to find probability of intersection.
For instance, in some corner cases AND product can be predicted empty if vectors
belong to different ranges.
@sa bm::bvector<>::find()
@sa bm::bvector<>::find_reverse()
@sa bm::bvector<>::find_range()
*/
/*! \file sample15.cpp
\brief Example: bvector<> methods to find last bit and bit-vectors effective range
*/
#include <stdlib.h>
#include <iostream>
#include <vector>
#include "bm.h"
using namespace std;
const unsigned MAX_VALUE = 10000000;
static
{
unsigned start = MAX_VALUE / (rand()%10);
for (unsigned i = start; i < MAX_VALUE; ++i)
{
if ((rand() % 10))
{
bv->set(i);
}
}
}
int main(void)
{
try
{
fill_bvector(&bv1);
fill_bvector(&bv2);
cout << "bv1 count = " << bv1.count() << endl;
cout << "bv2 count = " << bv2.count() << endl;
bool found;
found = bv1.find(first);
if (found)
cout << "bv1 first = " << first << endl;
found = bv1.find_reverse(last);
if (found)
cout << "bv1 last = " << last << endl;
found = bv2.find(first);
if (found)
cout << "bv2 first = " << first << endl;
found = bv2.find_reverse(last);
if (found)
cout << "bv2 last = " << last << endl;
found = bv1.find_range(first, last);
if (found)
cout << "bv1 range = [" << first << ", " << last << "]" << endl;
found = bv2.find_range(first, last);
if (found)
cout << "bv2 range = [" << first << ", " << last << "]" << endl;
}
catch(std::exception& ex)
{
std::cerr << ex.what() << std::endl;
return 1;
}
return 0;
}
Compressed bit-vector bvector<> container, set algebraic methods, traversal iterators.
Bitvector Bit-vector container with runtime compression of bits.
Definition bm.h:108
bool find(size_type &pos) const BMNOEXCEPT
Finds index of first 1 bit.
Definition bm.h:4035
size_type count() const BMNOEXCEPT
population cout (count of ON bits)
Definition bm.h:2194
bm::id_t size_type
Definition bm.h:117
bool find_range(size_type &first, size_type &last) const BMNOEXCEPT
Finds dynamic range of bit-vector [first, last].
Definition bm.h:4081
bvector< Alloc > & set(size_type n, bool val=true)
Sets bit n if val is true, clears bit n if val is false.
Definition bm.h:3581
bool find_reverse(size_type &pos) const BMNOEXCEPT
Finds last index of 1 bit.
Definition bm.h:3978
int main(void)
Definition sample1.cpp:38
static void fill_bvector(bm::bvector<> *bv1, bm::bvector<> *bv2)
Definition sample3.cpp:46
const unsigned MAX_VALUE
Definition sample3.cpp:40