| // -*- C++ -*- |
| |
| // Copyright (C) 2005, 2006 Free Software Foundation, Inc. |
| // |
| // This file is part of the GNU ISO C++ Library. This library is free |
| // software; you can redistribute it and/or modify it under the terms |
| // of the GNU General Public License as published by the Free Software |
| // Foundation; either version 2, or (at your option) any later |
| // version. |
| |
| // This library is distributed in the hope that it will be useful, but |
| // WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| // General Public License for more details. |
| |
| // You should have received a copy of the GNU General Public License |
| // along with this library; see the file COPYING. If not, write to |
| // the Free Software Foundation, 59 Temple Place - Suite 330, Boston, |
| // MA 02111-1307, USA. |
| |
| // As a special exception, you may use this file as part of a free |
| // software library without restriction. Specifically, if other files |
| // instantiate templates or use macros or inline functions from this |
| // file, or you compile this file and link it with other files to |
| // produce an executable, this file does not by itself cause the |
| // resulting executable to be covered by the GNU General Public |
| // License. This exception does not however invalidate any other |
| // reasons why the executable file might be covered by the GNU General |
| // Public License. |
| |
| // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL. |
| |
| // Permission to use, copy, modify, sell, and distribute this software |
| // is hereby granted without fee, provided that the above copyright |
| // notice appears in all copies, and that both that copyright notice |
| // and this permission notice appear in supporting documentation. None |
| // of the above authors, nor IBM Haifa Research Laboratories, make any |
| // representation about the suitability of this software for any |
| // purpose. It is provided "as is" without express or implied |
| // warranty. |
| |
| /** |
| * @file trie_prefix_search_example.cpp |
| * An example showing how to use a trie for searching |
| * for words with a given prefix. |
| */ |
| |
| /** |
| * This example shows how to use a PATRICIA trie for searching |
| * for words with a given prefix. |
| */ |
| |
| #include <cassert> |
| #include <iostream> |
| #include <ext/pb_ds/assoc_container.hpp> |
| #include <ext/pb_ds/trie_policy.hpp> |
| #include <ext/pb_ds/tag_and_trait.hpp> |
| |
| using namespace std; |
| using namespace pb_ds; |
| using namespace pb_ds; |
| |
| // A PATRICIA trie with a prefix-search node-updator type. Note that |
| // since the node updator is trie_prefix_search_node_update, then the |
| // container includes its method prefix_range. |
| typedef null_mapped_type mapped_type; |
| typedef string_trie_e_access_traits<> cmp_fn; |
| typedef pat_trie_tag tag_type; |
| |
| typedef trie<string, mapped_type, cmp_fn, tag_type, |
| trie_prefix_search_node_update> trie_type; |
| |
| // The following helper function takes a trie object and r_key, a |
| // const reference to a string, and prints all entries whose key |
| // includes r_key as a prefix. |
| void |
| print_prefix_match(const trie_type& t, const string& key) |
| { |
| typedef trie_type::const_iterator const_iterator; |
| typedef pair<const_iterator, const_iterator> pair_type; |
| |
| cout << "All keys whose prefix matches \"" << key << "\":" << endl; |
| |
| const pair_type match_range = t.prefix_range(key); |
| for (const_iterator it = match_range.first; it != match_range.second; ++it) |
| cout << *it << ' '; |
| cout << endl; |
| } |
| |
| int main() |
| { |
| trie_type t; |
| |
| // Insert some entries. |
| assert(t.insert("I").second == true); |
| assert(t.insert("wish").second == true); |
| assert(t.insert("that").second == true); |
| assert(t.insert("I").second == false); |
| assert(t.insert("could").second == true); |
| assert(t.insert("ever").second == true); |
| assert(t.insert("see").second == true); |
| assert(t.insert("a").second == true); |
| assert(t.insert("poem").second == true); |
| assert(t.insert("lovely").second == true); |
| assert(t.insert("as").second == true); |
| assert(t.insert("a").second == false); |
| assert(t.insert("trie").second == true); |
| |
| // Now search for prefixes. |
| print_prefix_match(t, ""); |
| print_prefix_match(t, "a"); |
| print_prefix_match(t, "as"); |
| print_prefix_match(t, "ad"); |
| print_prefix_match(t, "t"); |
| print_prefix_match(t, "tr"); |
| print_prefix_match(t, "trie"); |
| print_prefix_match(t, "zzz"); |
| |
| return 0; |
| } |
| |