[Lemon-commits] deba: r3393 - lemon/trunk/lemon

[Lemon SVN]

Author: deba
Date: Tue Nov 20 16:06:03 2007
New Revision: 3393

Added:
   lemon/trunk/lemon/nauty_reader.h
Modified:
   lemon/trunk/lemon/Makefile.am

Log:
Nauty graph6 reader



Modified: lemon/trunk/lemon/Makefile.am
==============================================================================
--- lemon/trunk/lemon/Makefile.am	(original)
+++ lemon/trunk/lemon/Makefile.am	Tue Nov 20 16:06:03 2007
@@ -100,6 +100,7 @@
 	lemon/mip_glpk.h \
 	lemon/mip_cplex.h \
 	lemon/nagamochi_ibaraki.h \
+	lemon/nauty_reader.h \
 	lemon/network_simplex.h \
 	lemon/path.h \
 	lemon/path_utils.h \

Added: lemon/trunk/lemon/nauty_reader.h
==============================================================================
--- (empty file)
+++ lemon/trunk/lemon/nauty_reader.h	Tue Nov 20 16:06:03 2007
@@ -0,0 +1,120 @@
+/* -*- C++ -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library
+ *
+ * Copyright (C) 2003-2007
+ * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+#ifndef LEMON_NAUTY_READER_H
+#define LEMON_NAUTY_READER_H
+
+#include <vector>
+#include <iostream>
+#include <string>
+
+
+/// \ingroup io_group
+///
+/// @defgroup nauty_group NAUTY format
+///
+/// \brief Read \e Nauty format
+///
+/// Tool to read graphs from \e Nauty format data
+
+/// \ingroup nauty_group
+/// \file
+/// \brief Nauty file reader.
+namespace lemon {
+
+  /// \ingroup nauty_group
+  ///
+  /// \brief Nauty file reader
+  ///
+  /// The \e geng program is in the \e gtools suite of the nauty
+  /// package. This tool can generate all non-isomorphic undirected
+  /// graphs with given node number from several classes (for example,
+  /// general, connected, biconnected, triangle-free, 4-cycle-free,
+  /// bipartite and graphs with given edge number and degree
+  /// constraints). This function reads a \e nauty \e graph6 \e format
+  /// line from the given stream and builds it in the given graph.
+  ///
+  /// The site of nauty package: http://cs.anu.edu.au/~bdm/nauty/
+  ///
+  /// For example, the number of all non-isomorphic connected graphs
+  /// can be computed with next code:
+  ///\code
+  /// int num = 0;
+  /// SmartUGraph ugraph;
+  /// while(readNauty(std::cin, ugraph)) {
+  ///   PlanarityChecking<SmartUGraph> pc(ugraph);
+  ///   if (pc.run()) ++num;
+  /// }
+  /// std::cout << "Number of planar graphs: " << num << std::endl;
+  ///\endcode
+  ///
+  /// The nauty files are quite huge, therefore instead of the direct
+  /// file generation the pipelining is recommended. The execution of
+  /// this program:
+  ///\code 
+  /// ./geng -c 10 | ./num_of_pg 
+  ///\endcode
+  template <typename UGraph>
+  std::istream& readNauty(std::istream& is, UGraph& ugraph) {
+    ugraph.clear();
+
+    std::string line;
+    if (getline(is, line)) {
+      int index = 0;
+    
+      int n;
+
+      if (line[index] == '>') {
+	index += 10; 
+      }
+
+      char c = line[index++]; c -= 63;
+      if (c != 63) {
+	n = int(c);
+      } else {
+	c = line[index++]; c -= 63;
+	n = (int(c) << 12);
+	c = line[index++]; c -= 63;
+	n |= (int(c) << 6);
+	c = line[index++]; c -= 63;
+	n |= int(c);      
+      }
+
+      std::vector<typename UGraph::Node> nodes;
+      for (int i = 0; i < n; ++i) {
+	nodes.push_back(ugraph.addNode());
+      }
+
+      int bit = -1;
+      for (int j = 0; j < n; ++j) {
+	for (int i = 0; i < j; ++i) {
+	  if (bit == -1) {
+	    c = line[index++]; c -= 63;
+	    bit = 5;
+	  }
+	  bool b = (c & (1 << (bit--))) != 0;
+
+	  ugraph.addEdge(nodes[i], nodes[j]);
+	}
+      }
+    }
+    return is;
+  }
+}
+
+#endif