diff -r e9c203fb003d -r 994c7df296c9 lemon/hypercube_graph.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lemon/hypercube_graph.h	Thu Dec 10 17:05:35 2009 +0100
@@ -0,0 +1,438 @@
+/* -*- mode: C++; indent-tabs-mode: nil; -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library.
+ *
+ * Copyright (C) 2003-2009
+ * 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 HYPERCUBE_GRAPH_H
+#define HYPERCUBE_GRAPH_H
+
+#include <vector>
+#include <lemon/core.h>
+#include <lemon/assert.h>
+#include <lemon/bits/graph_extender.h>
+
+///\ingroup graphs
+///\file
+///\brief HypercubeGraph class.
+
+namespace lemon {
+
+  class HypercubeGraphBase {
+
+  public:
+
+    typedef HypercubeGraphBase Graph;
+
+    class Node;
+    class Edge;
+    class Arc;
+
+  public:
+
+    HypercubeGraphBase() {}
+
+  protected:
+
+    void construct(int dim) {
+      LEMON_ASSERT(dim >= 1, "The number of dimensions must be at least 1.");
+      _dim = dim;
+      _node_num = 1 << dim;
+      _edge_num = dim * (1 << (dim-1));
+    }
+
+  public:
+
+    typedef True NodeNumTag;
+    typedef True EdgeNumTag;
+    typedef True ArcNumTag;
+
+    int nodeNum() const { return _node_num; }
+    int edgeNum() const { return _edge_num; }
+    int arcNum() const { return 2 * _edge_num; }
+
+    int maxNodeId() const { return _node_num - 1; }
+    int maxEdgeId() const { return _edge_num - 1; }
+    int maxArcId() const { return 2 * _edge_num - 1; }
+
+    static Node nodeFromId(int id) { return Node(id); }
+    static Edge edgeFromId(int id) { return Edge(id); }
+    static Arc arcFromId(int id) { return Arc(id); }
+
+    static int id(Node node) { return node._id; }
+    static int id(Edge edge) { return edge._id; }
+    static int id(Arc arc) { return arc._id; }
+
+    Node u(Edge edge) const {
+      int base = edge._id & ((1 << (_dim-1)) - 1);
+      int k = edge._id >> (_dim-1);
+      return ((base >> k) << (k+1)) | (base & ((1 << k) - 1));
+    }
+
+    Node v(Edge edge) const {
+      int base = edge._id & ((1 << (_dim-1)) - 1);
+      int k = edge._id >> (_dim-1);
+      return ((base >> k) << (k+1)) | (base & ((1 << k) - 1)) | (1 << k);
+    }
+
+    Node source(Arc arc) const {
+      return (arc._id & 1) == 1 ? u(arc) : v(arc);
+    }
+
+    Node target(Arc arc) const {
+      return (arc._id & 1) == 1 ? v(arc) : u(arc);
+    }
+
+    typedef True FindEdgeTag;
+    typedef True FindArcTag;
+
+    Edge findEdge(Node u, Node v, Edge prev = INVALID) const {
+      if (prev != INVALID) return INVALID;
+      int d = u._id ^ v._id;
+      int k = 0;
+      if (d == 0) return INVALID;
+      for ( ; (d & 1) == 0; d >>= 1) ++k;
+      if (d >> 1 != 0) return INVALID;
+      return (k << (_dim-1)) | ((u._id >> (k+1)) << k) |
+        (u._id & ((1 << k) - 1));
+    }
+
+    Arc findArc(Node u, Node v, Arc prev = INVALID) const {
+      Edge edge = findEdge(u, v, prev);
+      if (edge == INVALID) return INVALID;
+      int k = edge._id >> (_dim-1);
+      return ((u._id >> k) & 1) == 1 ? edge._id << 1 : (edge._id << 1) | 1;
+    }
+
+    class Node {
+      friend class HypercubeGraphBase;
+
+    protected:
+      int _id;
+      Node(int id) : _id(id) {}
+    public:
+      Node() {}
+      Node (Invalid) : _id(-1) {}
+      bool operator==(const Node node) const {return _id == node._id;}
+      bool operator!=(const Node node) const {return _id != node._id;}
+      bool operator<(const Node node) const {return _id < node._id;}
+    };
+
+    class Edge {
+      friend class HypercubeGraphBase;
+      friend class Arc;
+
+    protected:
+      int _id;
+
+      Edge(int id) : _id(id) {}
+
+    public:
+      Edge() {}
+      Edge (Invalid) : _id(-1) {}
+      bool operator==(const Edge edge) const {return _id == edge._id;}
+      bool operator!=(const Edge edge) const {return _id != edge._id;}
+      bool operator<(const Edge edge) const {return _id < edge._id;}
+    };
+
+    class Arc {
+      friend class HypercubeGraphBase;
+
+    protected:
+      int _id;
+
+      Arc(int id) : _id(id) {}
+
+    public:
+      Arc() {}
+      Arc (Invalid) : _id(-1) {}
+      operator Edge() const { return _id != -1 ? Edge(_id >> 1) : INVALID; }
+      bool operator==(const Arc arc) const {return _id == arc._id;}
+      bool operator!=(const Arc arc) const {return _id != arc._id;}
+      bool operator<(const Arc arc) const {return _id < arc._id;}
+    };
+
+    void first(Node& node) const {
+      node._id = _node_num - 1;
+    }
+
+    static void next(Node& node) {
+      --node._id;
+    }
+
+    void first(Edge& edge) const {
+      edge._id = _edge_num - 1;
+    }
+
+    static void next(Edge& edge) {
+      --edge._id;
+    }
+
+    void first(Arc& arc) const {
+      arc._id = 2 * _edge_num - 1;
+    }
+
+    static void next(Arc& arc) {
+      --arc._id;
+    }
+
+    void firstInc(Edge& edge, bool& dir, const Node& node) const {
+      edge._id = node._id >> 1;
+      dir = (node._id & 1) == 0;
+    }
+
+    void nextInc(Edge& edge, bool& dir) const {
+      Node n = dir ? u(edge) : v(edge);
+      int k = (edge._id >> (_dim-1)) + 1;
+      if (k < _dim) {
+        edge._id = (k << (_dim-1)) |
+          ((n._id >> (k+1)) << k) | (n._id & ((1 << k) - 1));
+        dir = ((n._id >> k) & 1) == 0;
+      } else {
+        edge._id = -1;
+        dir = true;
+      }
+    }
+
+    void firstOut(Arc& arc, const Node& node) const {
+      arc._id = ((node._id >> 1) << 1) | (~node._id & 1);
+    }
+
+    void nextOut(Arc& arc) const {
+      Node n = (arc._id & 1) == 1 ? u(arc) : v(arc);
+      int k = (arc._id >> _dim) + 1;
+      if (k < _dim) {
+        arc._id = (k << (_dim-1)) |
+          ((n._id >> (k+1)) << k) | (n._id & ((1 << k) - 1));
+        arc._id = (arc._id << 1) | (~(n._id >> k) & 1);
+      } else {
+        arc._id = -1;
+      }
+    }
+
+    void firstIn(Arc& arc, const Node& node) const {
+      arc._id = ((node._id >> 1) << 1) | (node._id & 1);
+    }
+
+    void nextIn(Arc& arc) const {
+      Node n = (arc._id & 1) == 1 ? v(arc) : u(arc);
+      int k = (arc._id >> _dim) + 1;
+      if (k < _dim) {
+        arc._id = (k << (_dim-1)) |
+          ((n._id >> (k+1)) << k) | (n._id & ((1 << k) - 1));
+        arc._id = (arc._id << 1) | ((n._id >> k) & 1);
+      } else {
+        arc._id = -1;
+      }
+    }
+
+    static bool direction(Arc arc) {
+      return (arc._id & 1) == 1;
+    }
+
+    static Arc direct(Edge edge, bool dir) {
+      return Arc((edge._id << 1) | (dir ? 1 : 0));
+    }
+
+    int dimension() const {
+      return _dim;
+    }
+
+    bool projection(Node node, int n) const {
+      return static_cast<bool>(node._id & (1 << n));
+    }
+
+    int dimension(Edge edge) const {
+      return edge._id >> (_dim-1);
+    }
+
+    int dimension(Arc arc) const {
+      return arc._id >> _dim;
+    }
+
+    int index(Node node) const {
+      return node._id;
+    }
+
+    Node operator()(int ix) const {
+      return Node(ix);
+    }
+
+  private:
+    int _dim;
+    int _node_num, _edge_num;
+  };
+
+
+  typedef GraphExtender<HypercubeGraphBase> ExtendedHypercubeGraphBase;
+
+  /// \ingroup graphs
+  ///
+  /// \brief Hypercube graph class
+  ///
+  /// This class implements a special graph type. The nodes of the graph
+  /// are indiced with integers with at most \c dim binary digits.
+  /// Two nodes are connected in the graph if and only if their indices
+  /// differ only on one position in the binary form.
+  ///
+  /// \note The type of the indices is chosen to \c int for efficiency
+  /// reasons. Thus the maximum dimension of this implementation is 26
+  /// (assuming that the size of \c int is 32 bit).
+  ///
+  /// This graph type fully conforms to the \ref concepts::Graph
+  /// "Graph concept".
+  class HypercubeGraph : public ExtendedHypercubeGraphBase {
+    typedef ExtendedHypercubeGraphBase Parent;
+
+  public:
+
+    /// \brief Constructs a hypercube graph with \c dim dimensions.
+    ///
+    /// Constructs a hypercube graph with \c dim dimensions.
+    HypercubeGraph(int dim) { construct(dim); }
+
+    /// \brief The number of dimensions.
+    ///
+    /// Gives back the number of dimensions.
+    int dimension() const {
+      return Parent::dimension();
+    }
+
+    /// \brief Returns \c true if the n'th bit of the node is one.
+    ///
+    /// Returns \c true if the n'th bit of the node is one.
+    bool projection(Node node, int n) const {
+      return Parent::projection(node, n);
+    }
+
+    /// \brief The dimension id of an edge.
+    ///
+    /// Gives back the dimension id of the given edge.
+    /// It is in the [0..dim-1] range.
+    int dimension(Edge edge) const {
+      return Parent::dimension(edge);
+    }
+
+    /// \brief The dimension id of an arc.
+    ///
+    /// Gives back the dimension id of the given arc.
+    /// It is in the [0..dim-1] range.
+    int dimension(Arc arc) const {
+      return Parent::dimension(arc);
+    }
+
+    /// \brief The index of a node.
+    ///
+    /// Gives back the index of the given node.
+    /// The lower bits of the integer describes the node.
+    int index(Node node) const {
+      return Parent::index(node);
+    }
+
+    /// \brief Gives back a node by its index.
+    ///
+    /// Gives back a node by its index.
+    Node operator()(int ix) const {
+      return Parent::operator()(ix);
+    }
+
+    /// \brief Number of nodes.
+    int nodeNum() const { return Parent::nodeNum(); }
+    /// \brief Number of edges.
+    int edgeNum() const { return Parent::edgeNum(); }
+    /// \brief Number of arcs.
+    int arcNum() const { return Parent::arcNum(); }
+
+    /// \brief Linear combination map.
+    ///
+    /// This map makes possible to give back a linear combination
+    /// for each node. It works like the \c std::accumulate function,
+    /// so it accumulates the \c bf binary function with the \c fv first
+    /// value. The map accumulates only on that positions (dimensions)
+    /// where the index of the node is one. The values that have to be
+    /// accumulated should be given by the \c begin and \c end iterators
+    /// and the length of this range should be equal to the dimension
+    /// number of the graph.
+    ///
+    ///\code
+    /// const int DIM = 3;
+    /// HypercubeGraph graph(DIM);
+    /// dim2::Point<double> base[DIM];
+    /// for (int k = 0; k < DIM; ++k) {
+    ///   base[k].x = rnd();
+    ///   base[k].y = rnd();
+    /// }
+    /// HypercubeGraph::HyperMap<dim2::Point<double> >
+    ///   pos(graph, base, base + DIM, dim2::Point<double>(0.0, 0.0));
+    ///\endcode
+    ///
+    /// \see HypercubeGraph
+    template <typename T, typename BF = std::plus<T> >
+    class HyperMap {
+    public:
+
+      /// \brief The key type of the map
+      typedef Node Key;
+      /// \brief The value type of the map
+      typedef T Value;
+
+      /// \brief Constructor for HyperMap.
+      ///
+      /// Construct a HyperMap for the given graph. The values that have
+      /// to be accumulated should be given by the \c begin and \c end
+      /// iterators and the length of this range should be equal to the
+      /// dimension number of the graph.
+      ///
+      /// This map accumulates the \c bf binary function with the \c fv
+      /// first value on that positions (dimensions) where the index of
+      /// the node is one.
+      template <typename It>
+      HyperMap(const Graph& graph, It begin, It end,
+               T fv = 0, const BF& bf = BF())
+        : _graph(graph), _values(begin, end), _first_value(fv), _bin_func(bf)
+      {
+        LEMON_ASSERT(_values.size() == graph.dimension(),
+                     "Wrong size of range");
+      }
+
+      /// \brief The partial accumulated value.
+      ///
+      /// Gives back the partial accumulated value.
+      Value operator[](const Key& k) const {
+        Value val = _first_value;
+        int id = _graph.index(k);
+        int n = 0;
+        while (id != 0) {
+          if (id & 1) {
+            val = _bin_func(val, _values[n]);
+          }
+          id >>= 1;
+          ++n;
+        }
+        return val;
+      }
+
+    private:
+      const Graph& _graph;
+      std::vector<T> _values;
+      T _first_value;
+      BF _bin_func;
+    };
+
+  };
+
+}
+
+#endif