BitMagic-C++: sample15.cpp Source File

BitMagic-C++

sample15.cpp
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1 /*
2 Copyright(c) 2002-2017 Anatoliy Kuznetsov(anatoliy_kuznetsov at yahoo.com)
3
4 Licensed under the Apache License, Version 2.0 (the "License");
5 you may not use this file except in compliance with the License.
6 You may obtain a copy of the License at
7
8 http://www.apache.org/licenses/LICENSE-2.0
9
10 Unless required by applicable law or agreed to in writing, software
11 distributed under the License is distributed on an "AS IS" BASIS,
12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 See the License for the specific language governing permissions and
14 limitations under the License.
15
16 For more information please visit: http://bitmagic.io
17 */
18
19 /** \example sample15.cpp
20 Example for finding first and last bits in bit-vector (dynamic range).
21
22 Ranges of bit-vectors can be used to find probability of intersection.
23 For instance, in some corner cases AND product can be predicted empty if vectors
24 belong to different ranges.
25
26 @sa bm::bvector<>::find()
27 @sa bm::bvector<>::find_reverse()
28 @sa bm::bvector<>::find_range()
29 */
30
31 /*! \file sample15.cpp
32 \brief Example: bvector<> methods to find last bit and bit-vectors effective range
33 */
34
35 #include <stdlib.h>
36 #include <iostream>
37 #include <vector>
38
39 #include "bm.h"
40
41 using namespace std;
42
43
44 const unsigned MAX_VALUE = 10000000;
45
46 static
47 void fill_bvector(bm::bvector<>* bv)
48 {
49 unsigned start = MAX_VALUE / (rand()%10);
50 for (unsigned i = start; i < MAX_VALUE; ++i)
51 {
52 if ((rand() % 10))
53 {
54 bv->set(i);
55 }
56 }
57 }
58
59
60 int main(void)
61 {
62 try
63 {
64 bm::bvector<> bv1;
65 bm::bvector<> bv2;
66
67 fill_bvector(&bv1);
68 fill_bvector(&bv2);
69
70 cout << "bv1 count = " << bv1.count() << endl;
71 cout << "bv2 count = " << bv2.count() << endl;
72
73 bool found;
74 bm::bvector<>::size_type first, last;
75
76 found = bv1.find(first);
77 if (found)
78 cout << "bv1 first = " << first << endl;
79
80 found = bv1.find_reverse(last);
81 if (found)
82 cout << "bv1 last = " << last << endl;
83
84 found = bv2.find(first);
85 if (found)
86 cout << "bv2 first = " << first << endl;
87
88 found = bv2.find_reverse(last);
89 if (found)
90 cout << "bv2 last = " << last << endl;
91
92 found = bv1.find_range(first, last);
93 if (found)
94 cout << "bv1 range = [" << first << ", " << last << "]" << endl;
95
96 found = bv2.find_range(first, last);
97 if (found)
98 cout << "bv2 range = [" << first << ", " << last << "]" << endl;
99
100 }
101 catch(std::exception& ex)
102 {
103 std::cerr << ex.what() << std::endl;
104 return 1;
105 }
106
107
108 return 0;
109 }
110
fill_bvector
static void fill_bvector(bm::bvector<> *bv)
Definition: sample15.cpp:47
main
int main(void)
Definition: sample15.cpp:60
bm::bvector<>
bm::bvector::set
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
bm::bvector::count
size_type count() const BMNOEXCEPT
population cout (count of ON bits)
Definition: bm.h:2194
MAX_VALUE
const unsigned MAX_VALUE
Definition: sample15.cpp:44
bm::bvector::find
bool find(size_type &pos) const BMNOEXCEPT
Finds index of first 1 bit.
Definition: bm.h:4035
bm::bvector::find_range
bool find_range(size_type &first, size_type &last) const BMNOEXCEPT
Finds dynamic range of bit-vector [first, last].
Definition: bm.h:4081
bm::bvector::size_type
bm::id_t size_type
Definition: bm.h:117
bm.h
Compressed bit-vector bvector<> container, set algebraic methods, traversal iterators.
bm::bvector::find_reverse
bool find_reverse(size_type &pos) const BMNOEXCEPT
Finds last index of 1 bit.
Definition: bm.h:3978