diff -r e9c203fb003d -r 994c7df296c9 lemon/grid_graph.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lemon/grid_graph.h Thu Dec 10 17:05:35 2009 +0100 @@ -0,0 +1,703 @@ +/* -*- 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 GRID_GRAPH_H +#define GRID_GRAPH_H + +#include +#include +#include +#include + +///\ingroup graphs +///\file +///\brief GridGraph class. + +namespace lemon { + + class GridGraphBase { + + public: + + typedef GridGraphBase Graph; + + class Node; + class Edge; + class Arc; + + public: + + GridGraphBase() {} + + protected: + + void construct(int width, int height) { + _width = width; _height = height; + _node_num = width * height; + _edge_num = 2 * _node_num - width - height; + _edge_limit = _node_num - _width; + } + + public: + + Node operator()(int i, int j) const { + LEMON_DEBUG(0 <= i && i < _width && + 0 <= j && j < _height, "Index out of range"); + return Node(i + j * _width); + } + + int col(Node n) const { + return n._id % _width; + } + + int row(Node n) const { + return n._id / _width; + } + + dim2::Point pos(Node n) const { + return dim2::Point(col(n), row(n)); + } + + int width() const { + return _width; + } + + int height() const { + return _height; + } + + 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; } + + Node u(Edge edge) const { + if (edge._id < _edge_limit) { + return edge._id; + } else { + return (edge._id - _edge_limit) % (_width - 1) + + (edge._id - _edge_limit) / (_width - 1) * _width; + } + } + + Node v(Edge edge) const { + if (edge._id < _edge_limit) { + return edge._id + _width; + } else { + return (edge._id - _edge_limit) % (_width - 1) + + (edge._id - _edge_limit) / (_width - 1) * _width + 1; + } + } + + 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); + } + + static int id(Node node) { return node._id; } + static int id(Edge edge) { return edge._id; } + static int id(Arc arc) { return arc._id; } + + 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);} + + typedef True FindEdgeTag; + typedef True FindArcTag; + + Edge findEdge(Node u, Node v, Edge prev = INVALID) const { + if (prev != INVALID) return INVALID; + if (v._id > u._id) { + if (v._id - u._id == _width) + return Edge(u._id); + if (v._id - u._id == 1 && u._id % _width < _width - 1) { + return Edge(u._id / _width * (_width - 1) + + u._id % _width + _edge_limit); + } + } else { + if (u._id - v._id == _width) + return Edge(v._id); + if (u._id - v._id == 1 && v._id % _width < _width - 1) { + return Edge(v._id / _width * (_width - 1) + + v._id % _width + _edge_limit); + } + } + return INVALID; + } + + Arc findArc(Node u, Node v, Arc prev = INVALID) const { + if (prev != INVALID) return INVALID; + if (v._id > u._id) { + if (v._id - u._id == _width) + return Arc((u._id << 1) | 1); + if (v._id - u._id == 1 && u._id % _width < _width - 1) { + return Arc(((u._id / _width * (_width - 1) + + u._id % _width + _edge_limit) << 1) | 1); + } + } else { + if (u._id - v._id == _width) + return Arc(v._id << 1); + if (u._id - v._id == 1 && v._id % _width < _width - 1) { + return Arc((v._id / _width * (_width - 1) + + v._id % _width + _edge_limit) << 1); + } + } + return INVALID; + } + + class Node { + friend class GridGraphBase; + + 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 GridGraphBase; + 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 GridGraphBase; + + 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;} + }; + + 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)); + } + + 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 firstOut(Arc& arc, const Node& node) const { + if (node._id % _width < _width - 1) { + arc._id = (_edge_limit + node._id % _width + + (node._id / _width) * (_width - 1)) << 1 | 1; + return; + } + if (node._id < _node_num - _width) { + arc._id = node._id << 1 | 1; + return; + } + if (node._id % _width > 0) { + arc._id = (_edge_limit + node._id % _width + + (node._id / _width) * (_width - 1) - 1) << 1; + return; + } + if (node._id >= _width) { + arc._id = (node._id - _width) << 1; + return; + } + arc._id = -1; + } + + void nextOut(Arc& arc) const { + int nid = arc._id >> 1; + if ((arc._id & 1) == 1) { + if (nid >= _edge_limit) { + nid = (nid - _edge_limit) % (_width - 1) + + (nid - _edge_limit) / (_width - 1) * _width; + if (nid < _node_num - _width) { + arc._id = nid << 1 | 1; + return; + } + } + if (nid % _width > 0) { + arc._id = (_edge_limit + nid % _width + + (nid / _width) * (_width - 1) - 1) << 1; + return; + } + if (nid >= _width) { + arc._id = (nid - _width) << 1; + return; + } + } else { + if (nid >= _edge_limit) { + nid = (nid - _edge_limit) % (_width - 1) + + (nid - _edge_limit) / (_width - 1) * _width + 1; + if (nid >= _width) { + arc._id = (nid - _width) << 1; + return; + } + } + } + arc._id = -1; + } + + void firstIn(Arc& arc, const Node& node) const { + if (node._id % _width < _width - 1) { + arc._id = (_edge_limit + node._id % _width + + (node._id / _width) * (_width - 1)) << 1; + return; + } + if (node._id < _node_num - _width) { + arc._id = node._id << 1; + return; + } + if (node._id % _width > 0) { + arc._id = (_edge_limit + node._id % _width + + (node._id / _width) * (_width - 1) - 1) << 1 | 1; + return; + } + if (node._id >= _width) { + arc._id = (node._id - _width) << 1 | 1; + return; + } + arc._id = -1; + } + + void nextIn(Arc& arc) const { + int nid = arc._id >> 1; + if ((arc._id & 1) == 0) { + if (nid >= _edge_limit) { + nid = (nid - _edge_limit) % (_width - 1) + + (nid - _edge_limit) / (_width - 1) * _width; + if (nid < _node_num - _width) { + arc._id = nid << 1; + return; + } + } + if (nid % _width > 0) { + arc._id = (_edge_limit + nid % _width + + (nid / _width) * (_width - 1) - 1) << 1 | 1; + return; + } + if (nid >= _width) { + arc._id = (nid - _width) << 1 | 1; + return; + } + } else { + if (nid >= _edge_limit) { + nid = (nid - _edge_limit) % (_width - 1) + + (nid - _edge_limit) / (_width - 1) * _width + 1; + if (nid >= _width) { + arc._id = (nid - _width) << 1 | 1; + return; + } + } + } + arc._id = -1; + } + + void firstInc(Edge& edge, bool& dir, const Node& node) const { + if (node._id % _width < _width - 1) { + edge._id = _edge_limit + node._id % _width + + (node._id / _width) * (_width - 1); + dir = true; + return; + } + if (node._id < _node_num - _width) { + edge._id = node._id; + dir = true; + return; + } + if (node._id % _width > 0) { + edge._id = _edge_limit + node._id % _width + + (node._id / _width) * (_width - 1) - 1; + dir = false; + return; + } + if (node._id >= _width) { + edge._id = node._id - _width; + dir = false; + return; + } + edge._id = -1; + dir = true; + } + + void nextInc(Edge& edge, bool& dir) const { + int nid = edge._id; + if (dir) { + if (nid >= _edge_limit) { + nid = (nid - _edge_limit) % (_width - 1) + + (nid - _edge_limit) / (_width - 1) * _width; + if (nid < _node_num - _width) { + edge._id = nid; + return; + } + } + if (nid % _width > 0) { + edge._id = _edge_limit + nid % _width + + (nid / _width) * (_width - 1) - 1; + dir = false; + return; + } + if (nid >= _width) { + edge._id = nid - _width; + dir = false; + return; + } + } else { + if (nid >= _edge_limit) { + nid = (nid - _edge_limit) % (_width - 1) + + (nid - _edge_limit) / (_width - 1) * _width + 1; + if (nid >= _width) { + edge._id = nid - _width; + return; + } + } + } + edge._id = -1; + dir = true; + } + + Arc right(Node n) const { + if (n._id % _width < _width - 1) { + return Arc(((_edge_limit + n._id % _width + + (n._id / _width) * (_width - 1)) << 1) | 1); + } else { + return INVALID; + } + } + + Arc left(Node n) const { + if (n._id % _width > 0) { + return Arc((_edge_limit + n._id % _width + + (n._id / _width) * (_width - 1) - 1) << 1); + } else { + return INVALID; + } + } + + Arc up(Node n) const { + if (n._id < _edge_limit) { + return Arc((n._id << 1) | 1); + } else { + return INVALID; + } + } + + Arc down(Node n) const { + if (n._id >= _width) { + return Arc((n._id - _width) << 1); + } else { + return INVALID; + } + } + + private: + int _width, _height; + int _node_num, _edge_num; + int _edge_limit; + }; + + + typedef GraphExtender ExtendedGridGraphBase; + + /// \ingroup graphs + /// + /// \brief Grid graph class + /// + /// This class implements a special graph type. The nodes of the + /// graph can be indexed by two integer \c (i,j) value where \c i is + /// in the \c [0..width()-1] range and j is in the \c + /// [0..height()-1] range. Two nodes are connected in the graph if + /// the indexes differ exactly on one position and exactly one is + /// the difference. The nodes of the graph can be indexed by position + /// with the \c operator()() function. The positions of the nodes can be + /// get with \c pos(), \c col() and \c row() members. The outgoing + /// arcs can be retrieved with the \c right(), \c up(), \c left() + /// and \c down() functions, where the bottom-left corner is the + /// origin. + /// + /// \image html grid_graph.png + /// \image latex grid_graph.eps "Grid graph" width=\textwidth + /// + /// A short example about the basic usage: + ///\code + /// GridGraph graph(rows, cols); + /// GridGraph::NodeMap val(graph); + /// for (int i = 0; i < graph.width(); ++i) { + /// for (int j = 0; j < graph.height(); ++j) { + /// val[graph(i, j)] = i + j; + /// } + /// } + ///\endcode + /// + /// This graph type fully conforms to the \ref concepts::Graph + /// "Graph concept". + class GridGraph : public ExtendedGridGraphBase { + typedef ExtendedGridGraphBase Parent; + + public: + + /// \brief Map to get the indices of the nodes as dim2::Point. + /// + /// Map to get the indices of the nodes as dim2::Point. + class IndexMap { + public: + /// \brief The key type of the map + typedef GridGraph::Node Key; + /// \brief The value type of the map + typedef dim2::Point Value; + + /// \brief Constructor + /// + /// Constructor + IndexMap(const GridGraph& graph) : _graph(graph) {} + + /// \brief The subscript operator + /// + /// The subscript operator. + Value operator[](Key key) const { + return _graph.pos(key); + } + + private: + const GridGraph& _graph; + }; + + /// \brief Map to get the column of the nodes. + /// + /// Map to get the column of the nodes. + class ColMap { + public: + /// \brief The key type of the map + typedef GridGraph::Node Key; + /// \brief The value type of the map + typedef int Value; + + /// \brief Constructor + /// + /// Constructor + ColMap(const GridGraph& graph) : _graph(graph) {} + + /// \brief The subscript operator + /// + /// The subscript operator. + Value operator[](Key key) const { + return _graph.col(key); + } + + private: + const GridGraph& _graph; + }; + + /// \brief Map to get the row of the nodes. + /// + /// Map to get the row of the nodes. + class RowMap { + public: + /// \brief The key type of the map + typedef GridGraph::Node Key; + /// \brief The value type of the map + typedef int Value; + + /// \brief Constructor + /// + /// Constructor + RowMap(const GridGraph& graph) : _graph(graph) {} + + /// \brief The subscript operator + /// + /// The subscript operator. + Value operator[](Key key) const { + return _graph.row(key); + } + + private: + const GridGraph& _graph; + }; + + /// \brief Constructor + /// + /// Construct a grid graph with given size. + GridGraph(int width, int height) { construct(width, height); } + + /// \brief Resize the graph + /// + /// Resize the graph. The function will fully destroy and rebuild + /// the graph. This cause that the maps of the graph will + /// reallocated automatically and the previous values will be + /// lost. + void resize(int width, int height) { + Parent::notifier(Arc()).clear(); + Parent::notifier(Edge()).clear(); + Parent::notifier(Node()).clear(); + construct(width, height); + Parent::notifier(Node()).build(); + Parent::notifier(Edge()).build(); + Parent::notifier(Arc()).build(); + } + + /// \brief The node on the given position. + /// + /// Gives back the node on the given position. + Node operator()(int i, int j) const { + return Parent::operator()(i, j); + } + + /// \brief Gives back the column index of the node. + /// + /// Gives back the column index of the node. + int col(Node n) const { + return Parent::col(n); + } + + /// \brief Gives back the row index of the node. + /// + /// Gives back the row index of the node. + int row(Node n) const { + return Parent::row(n); + } + + /// \brief Gives back the position of the node. + /// + /// Gives back the position of the node, ie. the (col,row) pair. + dim2::Point pos(Node n) const { + return Parent::pos(n); + } + + /// \brief Gives back the number of the columns. + /// + /// Gives back the number of the columns. + int width() const { + return Parent::width(); + } + + /// \brief Gives back the number of the rows. + /// + /// Gives back the number of the rows. + int height() const { + return Parent::height(); + } + + /// \brief Gives back the arc goes right from the node. + /// + /// Gives back the arc goes right from the node. If there is not + /// outgoing arc then it gives back INVALID. + Arc right(Node n) const { + return Parent::right(n); + } + + /// \brief Gives back the arc goes left from the node. + /// + /// Gives back the arc goes left from the node. If there is not + /// outgoing arc then it gives back INVALID. + Arc left(Node n) const { + return Parent::left(n); + } + + /// \brief Gives back the arc goes up from the node. + /// + /// Gives back the arc goes up from the node. If there is not + /// outgoing arc then it gives back INVALID. + Arc up(Node n) const { + return Parent::up(n); + } + + /// \brief Gives back the arc goes down from the node. + /// + /// Gives back the arc goes down from the node. If there is not + /// outgoing arc then it gives back INVALID. + Arc down(Node n) const { + return Parent::down(n); + } + + /// \brief Index map of the grid graph + /// + /// Just returns an IndexMap for the grid graph. + IndexMap indexMap() const { + return IndexMap(*this); + } + + /// \brief Row map of the grid graph + /// + /// Just returns a RowMap for the grid graph. + RowMap rowMap() const { + return RowMap(*this); + } + + /// \brief Column map of the grid graph + /// + /// Just returns a ColMap for the grid graph. + ColMap colMap() const { + return ColMap(*this); + } + + }; + +} +#endif