[360] | 1 | /* -*- mode: C++; indent-tabs-mode: nil; -*- |
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| 2 | * |
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| 3 | * This file is a part of LEMON, a generic C++ optimization library. |
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| 4 | * |
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[463] | 5 | * Copyright (C) 2003-2009 |
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[360] | 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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| 7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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| 8 | * |
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| 9 | * Permission to use, modify and distribute this software is granted |
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| 10 | * provided that this copyright notice appears in all copies. For |
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| 11 | * precise terms see the accompanying LICENSE file. |
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| 12 | * |
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| 13 | * This software is provided "AS IS" with no warranty of any kind, |
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| 14 | * express or implied, and with no claim as to its suitability for any |
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| 15 | * purpose. |
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| 16 | * |
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| 17 | */ |
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| 18 | |
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| 19 | #ifndef LEMON_NAUTY_READER_H |
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| 20 | #define LEMON_NAUTY_READER_H |
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| 21 | |
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| 22 | #include <vector> |
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| 23 | #include <iostream> |
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| 24 | #include <string> |
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| 25 | |
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| 26 | /// \ingroup nauty_group |
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| 27 | /// \file |
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| 28 | /// \brief Nauty file reader. |
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[363] | 29 | |
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[360] | 30 | namespace lemon { |
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| 31 | |
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| 32 | /// \ingroup nauty_group |
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| 33 | /// |
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| 34 | /// \brief Nauty file reader |
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| 35 | /// |
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| 36 | /// The \e geng program is in the \e gtools suite of the nauty |
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| 37 | /// package. This tool can generate all non-isomorphic undirected |
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[364] | 38 | /// graphs of several classes with given node number (e.g. |
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[360] | 39 | /// general, connected, biconnected, triangle-free, 4-cycle-free, |
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| 40 | /// bipartite and graphs with given edge number and degree |
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[370] | 41 | /// constraints). This function reads a \e nauty \e graph6 \e format |
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[360] | 42 | /// line from the given stream and builds it in the given graph. |
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| 43 | /// |
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| 44 | /// The site of nauty package: http://cs.anu.edu.au/~bdm/nauty/ |
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| 45 | /// |
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[364] | 46 | /// For example, the number of all non-isomorphic planar graphs |
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| 47 | /// can be computed with the following code. |
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[360] | 48 | ///\code |
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| 49 | /// int num = 0; |
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| 50 | /// SmartGraph graph; |
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[371] | 51 | /// while (readNautyGraph(graph, std::cin)) { |
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[362] | 52 | /// PlanarityChecking<SmartGraph> pc(graph); |
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[360] | 53 | /// if (pc.run()) ++num; |
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| 54 | /// } |
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| 55 | /// std::cout << "Number of planar graphs: " << num << std::endl; |
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| 56 | ///\endcode |
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| 57 | /// |
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| 58 | /// The nauty files are quite huge, therefore instead of the direct |
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[364] | 59 | /// file generation pipelining is recommended. For example, |
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[360] | 60 | ///\code |
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[364] | 61 | /// ./geng -c 10 | ./num_of_planar_graphs |
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[360] | 62 | ///\endcode |
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| 63 | template <typename Graph> |
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[371] | 64 | std::istream& readNautyGraph(Graph& graph, std::istream& is = std::cin) { |
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[360] | 65 | graph.clear(); |
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| 66 | |
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| 67 | std::string line; |
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| 68 | if (getline(is, line)) { |
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| 69 | int index = 0; |
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| 70 | |
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| 71 | int n; |
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| 72 | |
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| 73 | if (line[index] == '>') { |
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| 74 | index += 10; |
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| 75 | } |
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| 76 | |
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| 77 | char c = line[index++]; c -= 63; |
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| 78 | if (c != 63) { |
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| 79 | n = int(c); |
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| 80 | } else { |
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| 81 | c = line[index++]; c -= 63; |
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| 82 | n = (int(c) << 12); |
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| 83 | c = line[index++]; c -= 63; |
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| 84 | n |= (int(c) << 6); |
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| 85 | c = line[index++]; c -= 63; |
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| 86 | n |= int(c); |
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| 87 | } |
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| 88 | |
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| 89 | std::vector<typename Graph::Node> nodes; |
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| 90 | for (int i = 0; i < n; ++i) { |
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| 91 | nodes.push_back(graph.addNode()); |
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| 92 | } |
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| 93 | |
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| 94 | int bit = -1; |
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| 95 | for (int j = 0; j < n; ++j) { |
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| 96 | for (int i = 0; i < j; ++i) { |
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| 97 | if (bit == -1) { |
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| 98 | c = line[index++]; c -= 63; |
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| 99 | bit = 5; |
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| 100 | } |
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| 101 | bool b = (c & (1 << (bit--))) != 0; |
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| 102 | |
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| 103 | if (b) { |
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| 104 | graph.addEdge(nodes[i], nodes[j]); |
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| 105 | } |
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| 106 | } |
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| 107 | } |
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| 108 | } |
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| 109 | return is; |
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| 110 | } |
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| 111 | } |
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| 112 | |
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| 113 | #endif |
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