| // -*- C++ -*- |
| |
| // Copyright (C) 2005, 2006, 2009 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 3, 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 COPYING3. If not see |
| // <http://www.gnu.org/licenses/>. |
| |
| |
| // 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 tree_order_statistics_example.cpp |
| * An example showing how to use functors for order-statistics |
| * in tree-based containers. |
| */ |
| |
| /** |
| * In some cases tree structure can be used for various purposes asides |
| * from storing entries by key order. |
| * This example shows how a tree-based container can be used for |
| * order-statistics, i.e., for determining the order of each key |
| * in the (ordered) sequence of keys stored within the container object. |
| */ |
| |
| #include <cassert> |
| #include <ext/pb_ds/assoc_container.hpp> |
| #include <ext/pb_ds/tree_policy.hpp> |
| |
| using namespace std; |
| using namespace __gnu_pbds; |
| |
| // A red-black tree table storing ints and their order |
| // statistics. Note that since the tree uses |
| // tree_order_statistics_node_update as its update policy, then it |
| // includes its methods by_order and order_of_key. |
| typedef |
| tree< |
| int, |
| null_mapped_type, |
| less<int>, |
| rb_tree_tag, |
| // This policy updates nodes' metadata for order statistics. |
| tree_order_statistics_node_update> |
| set_t; |
| |
| int main() |
| { |
| // Insert some entries into s. |
| set_t s; |
| s.insert(12); |
| s.insert(505); |
| s.insert(30); |
| s.insert(1000); |
| s.insert(10000); |
| s.insert(100); |
| |
| // The order of the keys should be: 12, 30, 100, 505, 1000, 10000. |
| assert(*s.find_by_order(0) == 12); |
| assert(*s.find_by_order(1) == 30); |
| assert(*s.find_by_order(2) == 100); |
| assert(*s.find_by_order(3) == 505); |
| assert(*s.find_by_order(4) == 1000); |
| assert(*s.find_by_order(5) == 10000); |
| assert(s.find_by_order(6) == s.end()); |
| |
| // The order of the keys should be: 12, 30, 100, 505, 1000, 10000. |
| assert(s.order_of_key(10) == 0); |
| assert(s.order_of_key(12) == 0); |
| assert(s.order_of_key(15) == 1); |
| assert(s.order_of_key(30) == 1); |
| assert(s.order_of_key(99) == 2); |
| assert(s.order_of_key(100) == 2); |
| assert(s.order_of_key(505) == 3); |
| assert(s.order_of_key(1000) == 4); |
| assert(s.order_of_key(10000) == 5); |
| assert(s.order_of_key(9999999) == 6); |
| |
| // Erase an entry. |
| s.erase(30); |
| |
| // The order of the keys should be: 12, 100, 505, 1000, 10000. |
| assert(*s.find_by_order(0) == 12); |
| assert(*s.find_by_order(1) == 100); |
| assert(*s.find_by_order(2) == 505); |
| assert(*s.find_by_order(3) == 1000); |
| assert(*s.find_by_order(4) == 10000); |
| assert(s.find_by_order(5) == s.end()); |
| |
| // The order of the keys should be: 12, 100, 505, 1000, 10000. |
| assert(s.order_of_key(10) == 0); |
| assert(s.order_of_key(12) == 0); |
| assert(s.order_of_key(100) == 1); |
| assert(s.order_of_key(505) == 2); |
| assert(s.order_of_key(707) == 3); |
| assert(s.order_of_key(1000) == 3); |
| assert(s.order_of_key(1001) == 4); |
| assert(s.order_of_key(10000) == 4); |
| assert(s.order_of_key(100000) == 5); |
| assert(s.order_of_key(9999999) == 5); |
| |
| return 0; |
| } |
| |