1 // -*- C++ -*-
2
3 // Copyright (C) 2005-2019 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the terms
7 // of the GNU General Public License as published by the Free Software
8 // Foundation; either version 3, or (at your option) any later
9 // version.
10
11 // This library is distributed in the hope that it will be useful, but
12 // WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 // General Public License for more details.
15
16 // You should have received a copy of the GNU General Public License
17 // along with this library; see the file COPYING3. If not see
18 // <http://www.gnu.org/licenses/>.
19
20
21 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
22
23 // Permission to use, copy, modify, sell, and distribute this software
24 // is hereby granted without fee, provided that the above copyright
25 // notice appears in all copies, and that both that copyright notice
26 // and this permission notice appear in supporting documentation. None
27 // of the above authors, nor IBM Haifa Research Laboratories, make any
28 // representation about the suitability of this software for any
29 // purpose. It is provided "as is" without express or implied
30 // warranty.
31
32 /**
33 * @file trie_split_example.cpp
34 * A basic example showing how to split trie-based container objects.
35 */
36
37 /**
38 * This example shows how to split trie based containers, i.e., the opposite
39 * of a join operation.
40 */
41
42 #include <string>
43 #include <cassert>
44 #include <ext/pb_ds/assoc_container.hpp>
45
46 using namespace std;
47 using namespace __gnu_pbds;
48
main()49 int main()
50 {
51 // A PATRICIA trie table mapping strings to chars.
52 typedef trie<string, char> map_type;
53
54 // A map_type object.
55 map_type r;
56
57 // Inserts some entries into r.
58 for (int i = 0; i < 100; ++ i)
59 r.insert(make_pair(string(i, 'a'), 'b'));
60
61 // Now split r into a different map_type object.
62
63 // larger_r will hold the larger values following the split.
64 map_type larger_r;
65
66 // Split all elements with key larger than 'a'^1000 into larger_r.
67 // This is exception free.
68 r.split(string(1000, 'a'), larger_r);
69
70 // Since there were no elements with key larger than 'a'^1000, r
71 // should be unchanged.
72 assert(r.size() == 100);
73 assert(r.begin()->first == string(""));
74
75 // Now perform a split which actually changes the content of r.
76
77 // Split all elements with key larger than "aaa" into larger_r.
78 r.split(string("aaa"), larger_r);
79
80 assert(r.size() == 4);
81 assert(larger_r.begin()->first == string("aaaa"));
82
83 return 0;
84 }
85
86