1 | /* -*- mode: C++; indent-tabs-mode: nil; -*- |
---|
2 | * |
---|
3 | * This file is a part of LEMON, a generic C++ optimization library. |
---|
4 | * |
---|
5 | * Copyright (C) 2003-2008 |
---|
6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
---|
7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
---|
8 | * |
---|
9 | * Permission to use, modify and distribute this software is granted |
---|
10 | * provided that this copyright notice appears in all copies. For |
---|
11 | * precise terms see the accompanying LICENSE file. |
---|
12 | * |
---|
13 | * This software is provided "AS IS" with no warranty of any kind, |
---|
14 | * express or implied, and with no claim as to its suitability for any |
---|
15 | * purpose. |
---|
16 | * |
---|
17 | */ |
---|
18 | |
---|
19 | #ifndef LEMON_NAUTY_READER_H |
---|
20 | #define LEMON_NAUTY_READER_H |
---|
21 | |
---|
22 | #include <vector> |
---|
23 | #include <iostream> |
---|
24 | #include <string> |
---|
25 | |
---|
26 | /// \ingroup nauty_group |
---|
27 | /// \file |
---|
28 | /// \brief Nauty file reader. |
---|
29 | |
---|
30 | namespace lemon { |
---|
31 | |
---|
32 | /// \ingroup nauty_group |
---|
33 | /// |
---|
34 | /// \brief Nauty file reader |
---|
35 | /// |
---|
36 | /// The \e geng program is in the \e gtools suite of the nauty |
---|
37 | /// package. This tool can generate all non-isomorphic undirected |
---|
38 | /// graphs of several classes with given node number (e.g. |
---|
39 | /// general, connected, biconnected, triangle-free, 4-cycle-free, |
---|
40 | /// bipartite and graphs with given edge number and degree |
---|
41 | /// constraints). This function reads a \e nauty \e graph \e format |
---|
42 | /// line from the given stream and builds it in the given graph. |
---|
43 | /// |
---|
44 | /// The site of nauty package: http://cs.anu.edu.au/~bdm/nauty/ |
---|
45 | /// |
---|
46 | /// For example, the number of all non-isomorphic planar graphs |
---|
47 | /// can be computed with the following code. |
---|
48 | ///\code |
---|
49 | /// int num = 0; |
---|
50 | /// SmartGraph graph; |
---|
51 | /// while (readNauty(graph, std::cin)) { |
---|
52 | /// PlanarityChecking<SmartGraph> pc(graph); |
---|
53 | /// if (pc.run()) ++num; |
---|
54 | /// } |
---|
55 | /// std::cout << "Number of planar graphs: " << num << std::endl; |
---|
56 | ///\endcode |
---|
57 | /// |
---|
58 | /// The nauty files are quite huge, therefore instead of the direct |
---|
59 | /// file generation pipelining is recommended. For example, |
---|
60 | ///\code |
---|
61 | /// ./geng -c 10 | ./num_of_planar_graphs |
---|
62 | ///\endcode |
---|
63 | template <typename Graph> |
---|
64 | std::istream& readNauty(Graph& graph, std::istream& is = std::cin) { |
---|
65 | graph.clear(); |
---|
66 | |
---|
67 | std::string line; |
---|
68 | if (getline(is, line)) { |
---|
69 | int index = 0; |
---|
70 | |
---|
71 | int n; |
---|
72 | |
---|
73 | if (line[index] == '>') { |
---|
74 | index += 10; |
---|
75 | } |
---|
76 | |
---|
77 | char c = line[index++]; c -= 63; |
---|
78 | if (c != 63) { |
---|
79 | n = int(c); |
---|
80 | } else { |
---|
81 | c = line[index++]; c -= 63; |
---|
82 | n = (int(c) << 12); |
---|
83 | c = line[index++]; c -= 63; |
---|
84 | n |= (int(c) << 6); |
---|
85 | c = line[index++]; c -= 63; |
---|
86 | n |= int(c); |
---|
87 | } |
---|
88 | |
---|
89 | std::vector<typename Graph::Node> nodes; |
---|
90 | for (int i = 0; i < n; ++i) { |
---|
91 | nodes.push_back(graph.addNode()); |
---|
92 | } |
---|
93 | |
---|
94 | int bit = -1; |
---|
95 | for (int j = 0; j < n; ++j) { |
---|
96 | for (int i = 0; i < j; ++i) { |
---|
97 | if (bit == -1) { |
---|
98 | c = line[index++]; c -= 63; |
---|
99 | bit = 5; |
---|
100 | } |
---|
101 | bool b = (c & (1 << (bit--))) != 0; |
---|
102 | |
---|
103 | if (b) { |
---|
104 | graph.addEdge(nodes[i], nodes[j]); |
---|
105 | } |
---|
106 | } |
---|
107 | } |
---|
108 | } |
---|
109 | return is; |
---|
110 | } |
---|
111 | } |
---|
112 | |
---|
113 | #endif |
---|