kpeter@334: /* -*- mode: C++; indent-tabs-mode: nil; -*-
kpeter@334:  *
kpeter@334:  * This file is a part of LEMON, a generic C++ optimization library.
kpeter@334:  *
kpeter@334:  * Copyright (C) 2003-2008
kpeter@334:  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
kpeter@334:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
kpeter@334:  *
kpeter@334:  * Permission to use, modify and distribute this software is granted
kpeter@334:  * provided that this copyright notice appears in all copies. For
kpeter@334:  * precise terms see the accompanying LICENSE file.
kpeter@334:  *
kpeter@334:  * This software is provided "AS IS" with no warranty of any kind,
kpeter@334:  * express or implied, and with no claim as to its suitability for any
kpeter@334:  * purpose.
kpeter@334:  *
kpeter@334:  */
kpeter@334: 
kpeter@334: #ifndef GRID_GRAPH_H
kpeter@334: #define GRID_GRAPH_H
kpeter@334: 
kpeter@334: #include <iostream>
kpeter@334: #include <lemon/core.h>
kpeter@334: #include <lemon/assert.h>
kpeter@334: 
kpeter@334: #include <lemon/bits/base_extender.h>
kpeter@334: #include <lemon/bits/graph_extender.h>
kpeter@334: 
kpeter@334: #include <lemon/dim2.h>
kpeter@334: 
kpeter@334: ///\ingroup graphs
kpeter@334: ///\file
kpeter@334: ///\brief GridGraph class.
kpeter@334: 
kpeter@334: namespace lemon {
kpeter@334: 
kpeter@334:   class GridGraphBase {
kpeter@334: 
kpeter@334:   public:
kpeter@334: 
kpeter@334:     typedef GridGraphBase Graph;
kpeter@334: 
kpeter@334:     class Node;
kpeter@334:     class Arc;
kpeter@334: 
kpeter@334:   public:
kpeter@334: 
kpeter@334:     GridGraphBase() {}
kpeter@334: 
kpeter@334:   protected:
kpeter@334: 
kpeter@334:     void construct(int w, int h) {
kpeter@334:       _height = h; _width = w;
kpeter@334:       _nodeNum = h * w; _arcNum = 2 * _nodeNum - w - h;
kpeter@334:       _arcLimit = _nodeNum - w;
kpeter@334:     }
kpeter@334: 
kpeter@334:     Arc _down(Node n) const {
kpeter@334:       if (n.id < _nodeNum - _width) {
kpeter@334:         return Arc(n.id);
kpeter@334:       } else {
kpeter@334:         return INVALID;
kpeter@334:       }
kpeter@334:     }
kpeter@334: 
kpeter@334:     Arc _up(Node n) const {
kpeter@334:       if (n.id >= _width) {
kpeter@334:         return Arc(n.id - _width);
kpeter@334:       } else {
kpeter@334:         return INVALID;
kpeter@334:       }
kpeter@334:     }
kpeter@334: 
kpeter@334:     Arc _right(Node n) const {
kpeter@334:       if (n.id % _width < _width - 1) {
kpeter@334:         return _arcLimit + n.id % _width + (n.id / _width) * (_width - 1);
kpeter@334:       } else {
kpeter@334:         return INVALID;
kpeter@334:       }
kpeter@334:     }
kpeter@334: 
kpeter@334:     Arc _left(Node n) const {
kpeter@334:       if (n.id % _width > 0) {
kpeter@334:         return _arcLimit + n.id % _width + (n.id / _width) * (_width - 1) - 1;
kpeter@334:       } else {
kpeter@334:         return INVALID;
kpeter@334:       }
kpeter@334:     }
kpeter@334: 
kpeter@334:   public:
kpeter@334: 
kpeter@334:     Node operator()(int i, int j) const {
kpeter@334:       LEMON_ASSERT(0 <= i && i < width() &&
kpeter@334:                    0 <= j && j < height(), "lemon::GridGraph::IndexError");
kpeter@334:       return Node(i + j * _width);
kpeter@334:     }
kpeter@334: 
kpeter@334:     int row(Node n) const {
kpeter@334:       return n.id / _width;
kpeter@334:     }
kpeter@334: 
kpeter@334:     int col(Node n) const {
kpeter@334:       return n.id % _width;
kpeter@334:     }
kpeter@334: 
kpeter@334:     int width() const {
kpeter@334:       return _width;
kpeter@334:     }
kpeter@334: 
kpeter@334:     int height() const {
kpeter@334:       return _height;
kpeter@334:     }
kpeter@334: 
kpeter@334:     typedef True NodeNumTag;
kpeter@334:     typedef True ArcNumTag;
kpeter@334: 
kpeter@334:     int nodeNum() const { return _nodeNum; }
kpeter@334:     int arcNum() const { return _arcNum; }
kpeter@334: 
kpeter@334:     int maxNodeId() const { return nodeNum() - 1; }
kpeter@334:     int maxArcId() const { return arcNum() - 1; }
kpeter@334: 
kpeter@334:     Node source(Arc e) const {
kpeter@334:       if (e.id < _arcLimit) {
kpeter@334:         return e.id;
kpeter@334:       } else {
kpeter@334:         return (e.id - _arcLimit) % (_width - 1) +
kpeter@334:           (e.id - _arcLimit) / (_width - 1) * _width;
kpeter@334:       }
kpeter@334:     }
kpeter@334: 
kpeter@334:     Node target(Arc e) const {
kpeter@334:       if (e.id < _arcLimit) {
kpeter@334:         return e.id + _width;
kpeter@334:       } else {
kpeter@334:         return (e.id - _arcLimit) % (_width - 1) +
kpeter@334:           (e.id - _arcLimit) / (_width - 1) * _width + 1;
kpeter@334:       }
kpeter@334:     }
kpeter@334: 
kpeter@334:     static int id(Node v) { return v.id; }
kpeter@334:     static int id(Arc e) { return e.id; }
kpeter@334: 
kpeter@334:     static Node nodeFromId(int id) { return Node(id);}
kpeter@334: 
kpeter@334:     static Arc arcFromId(int id) { return Arc(id);}
kpeter@334: 
kpeter@334:     typedef True FindArcTag;
kpeter@334: 
kpeter@334:     Arc findArc(Node u, Node v, Arc prev = INVALID) const {
kpeter@334:       if (prev != INVALID) return INVALID;
kpeter@334:       if (v.id - u.id == _width) return Arc(u.id);
kpeter@334:       if (v.id - u.id == 1 && u.id % _width < _width - 1) {
kpeter@334:         return Arc(u.id / _width * (_width - 1) +
kpeter@334:                    u.id % _width + _arcLimit);
kpeter@334:       }
kpeter@334:       return INVALID;
kpeter@334:     }
kpeter@334: 
kpeter@334:     class Node {
kpeter@334:       friend class GridGraphBase;
kpeter@334: 
kpeter@334:     protected:
kpeter@334:       int id;
kpeter@334:       Node(int _id) : id(_id) {}
kpeter@334:     public:
kpeter@334:       Node() {}
kpeter@334:       Node (Invalid) { id = -1; }
kpeter@334:       bool operator==(const Node node) const { return id == node.id; }
kpeter@334:       bool operator!=(const Node node) const { return id != node.id; }
kpeter@334:       bool operator<(const Node node) const { return id < node.id; }
kpeter@334:     };
kpeter@334: 
kpeter@334:     class Arc {
kpeter@334:       friend class GridGraphBase;
kpeter@334: 
kpeter@334:     protected:
kpeter@334:       int id;
kpeter@334:       Arc(int _id) : id(_id) {}
kpeter@334:     public:
kpeter@334:       Arc() {}
kpeter@334:       Arc (Invalid) { id = -1; }
kpeter@334:       bool operator==(const Arc arc) const { return id == arc.id; }
kpeter@334:       bool operator!=(const Arc arc) const { return id != arc.id; }
kpeter@334:       bool operator<(const Arc arc) const { return id < arc.id; }
kpeter@334:     };
kpeter@334: 
kpeter@334:     void first(Node& node) const {
kpeter@334:       node.id = nodeNum() - 1;
kpeter@334:     }
kpeter@334: 
kpeter@334:     static void next(Node& node) {
kpeter@334:       --node.id;
kpeter@334:     }
kpeter@334: 
kpeter@334:     void first(Arc& arc) const {
kpeter@334:       arc.id = arcNum() - 1;
kpeter@334:     }
kpeter@334: 
kpeter@334:     static void next(Arc& arc) {
kpeter@334:       --arc.id;
kpeter@334:     }
kpeter@334: 
kpeter@334:     void firstOut(Arc& arc, const Node& node) const {
kpeter@334:       if (node.id < _nodeNum - _width) {
kpeter@334:         arc.id = node.id;
kpeter@334:       } else if (node.id % _width < _width - 1) {
kpeter@334:         arc.id = _arcLimit + node.id % _width +
kpeter@334:           (node.id / _width) * (_width - 1);
kpeter@334:       } else {
kpeter@334:         arc.id = -1;
kpeter@334:       }
kpeter@334:     }
kpeter@334: 
kpeter@334:     void nextOut(Arc& arc) const {
kpeter@334:       if (arc.id >= _arcLimit) {
kpeter@334:         arc.id = -1;
kpeter@334:       } else if (arc.id % _width < _width - 1) {
kpeter@334:         arc.id = _arcLimit + arc.id % _width +
kpeter@334:           (arc.id / _width) * (_width - 1);
kpeter@334:       } else {
kpeter@334:         arc.id = -1;
kpeter@334:       }
kpeter@334:     }
kpeter@334: 
kpeter@334:     void firstIn(Arc& arc, const Node& node) const {
kpeter@334:       if (node.id >= _width) {
kpeter@334:         arc.id = node.id - _width;
kpeter@334:       } else if (node.id % _width > 0) {
kpeter@334:         arc.id = _arcLimit + node.id % _width +
kpeter@334:           (node.id / _width) * (_width - 1) - 1;
kpeter@334:       } else {
kpeter@334:         arc.id = -1;
kpeter@334:       }
kpeter@334:     }
kpeter@334: 
kpeter@334:     void nextIn(Arc& arc) const {
kpeter@334:       if (arc.id >= _arcLimit) {
kpeter@334:         arc.id = -1;
kpeter@334:       } else if (arc.id % _width > 0) {
kpeter@334:         arc.id = _arcLimit + arc.id % _width +
kpeter@334:           (arc.id / _width + 1) * (_width - 1) - 1;
kpeter@334:       } else {
kpeter@334:         arc.id = -1;
kpeter@334:       }
kpeter@334:     }
kpeter@334: 
kpeter@334:   private:
kpeter@334:     int _width, _height;
kpeter@334:     int _nodeNum, _arcNum;
kpeter@334:     int _arcLimit;
kpeter@334:   };
kpeter@334: 
kpeter@334:   typedef GraphExtender<UndirDigraphExtender<GridGraphBase> >
kpeter@334:     ExtendedGridGraphBase;
kpeter@334: 
kpeter@334:   /// \ingroup graphs
kpeter@334:   ///
kpeter@334:   /// \brief Grid graph class
kpeter@334:   ///
kpeter@334:   /// This class implements a special graph type. The nodes of the
kpeter@334:   /// graph can be indiced by two integer \c (i,j) value where \c i
kpeter@334:   /// is in the \c [0,width) range and j is in the [0, height) range.
kpeter@334:   /// Two nodes are connected in the graph if the indices differ only
kpeter@334:   /// on one position and only one is the difference.
kpeter@334:   ///
kpeter@334:   /// \image html grid_graph.png
kpeter@334:   /// \image latex grid_graph.eps "Grid graph" width=\textwidth
kpeter@334:   ///
kpeter@334:   /// The graph can be indiced in the following way:
kpeter@334:   ///\code
kpeter@334:   /// GridGraph gr(w, h);
kpeter@334:   /// GridGraph::NodeMap<int> val(gr);
kpeter@334:   /// for (int i = 0; i < gr.width(); ++i) {
kpeter@334:   ///   for (int j = 0; j < gr.height(); ++j) {
kpeter@334:   ///     val[gr(i, j)] = i + j;
kpeter@334:   ///   }
kpeter@334:   /// }
kpeter@334:   ///\endcode
kpeter@334:   ///
kpeter@334:   /// This graph type is fully conform to the \ref concepts::Graph
kpeter@334:   /// "Undirected Graph" concept, and it also has an important extra
kpeter@334:   /// feature that its maps are real \ref concepts::ReferenceMap
kpeter@334:   /// "reference map"s.
kpeter@334:   class GridGraph : public ExtendedGridGraphBase {
kpeter@334:   public:
kpeter@334: 
kpeter@334:     typedef ExtendedGridGraphBase Parent;
kpeter@334: 
kpeter@334:     /// \brief Map to get the indices of the nodes as dim2::Point<int>.
kpeter@334:     ///
kpeter@334:     /// Map to get the indices of the nodes as dim2::Point<int>.
kpeter@334:     class IndexMap {
kpeter@334:     public:
kpeter@334:       /// The key type of the map
kpeter@334:       typedef GridGraph::Node Key;
kpeter@334:       /// The value type of the map
kpeter@334:       typedef dim2::Point<int> Value;
kpeter@334: 
kpeter@334:       /// Constructor
kpeter@334:       IndexMap(const GridGraph& graph) : _graph(graph) {}
kpeter@334: 
kpeter@334:       /// The subscript operator
kpeter@334:       Value operator[](const Key& key) const {
kpeter@334:         return dim2::Point<int>(_graph.row(key), _graph.col(key));
kpeter@334:       }
kpeter@334: 
kpeter@334:     private:
kpeter@334:       const GridGraph& _graph;
kpeter@334:     };
kpeter@334: 
kpeter@334:     /// \brief Map to get the row of the nodes.
kpeter@334:     ///
kpeter@334:     /// Map to get the row of the nodes.
kpeter@334:     class RowMap {
kpeter@334:     public:
kpeter@334:       /// The key type of the map
kpeter@334:       typedef GridGraph::Node Key;
kpeter@334:       /// The value type of the map
kpeter@334:       typedef int Value;
kpeter@334: 
kpeter@334:       /// Constructor
kpeter@334:       RowMap(const GridGraph& graph) : _graph(graph) {}
kpeter@334: 
kpeter@334:       /// The subscript operator
kpeter@334:       Value operator[](const Key& key) const {
kpeter@334:         return _graph.row(key);
kpeter@334:       }
kpeter@334: 
kpeter@334:     private:
kpeter@334:       const GridGraph& _graph;
kpeter@334:     };
kpeter@334: 
kpeter@334:     /// \brief Map to get the column of the nodes.
kpeter@334:     ///
kpeter@334:     /// Map to get the column of the nodes.
kpeter@334:     class ColMap {
kpeter@334:     public:
kpeter@334:       /// The key type of the map
kpeter@334:       typedef GridGraph::Node Key;
kpeter@334:       /// The value type of the map
kpeter@334:       typedef int Value;
kpeter@334: 
kpeter@334:       /// Constructor
kpeter@334:       ColMap(const GridGraph& graph) : _graph(graph) {}
kpeter@334: 
kpeter@334:       /// The subscript operator
kpeter@334:       Value operator[](const Key& key) const {
kpeter@334:         return _graph.col(key);
kpeter@334:       }
kpeter@334: 
kpeter@334:     private:
kpeter@334:       const GridGraph& _graph;
kpeter@334:     };
kpeter@334: 
kpeter@334:     /// \brief Constructor
kpeter@334:     ///
kpeter@334:     /// Constructor.
kpeter@334:     /// \param width The width of the grid.
kpeter@334:     /// \param height The height of the grid.
kpeter@334:     GridGraph(int width, int height) { construct(width, height); }
kpeter@334: 
kpeter@334:     /// \brief Resize the graph
kpeter@334:     ///
kpeter@334:     /// Resize the grid.
kpeter@334:     void resize(int width, int height) {
kpeter@334:       Parent::notifier(Arc()).clear();
kpeter@334:       Parent::notifier(Edge()).clear();
kpeter@334:       Parent::notifier(Node()).clear();
kpeter@334:       construct(width, height);
kpeter@334:       Parent::notifier(Node()).build();
kpeter@334:       Parent::notifier(Edge()).build();
kpeter@334:       Parent::notifier(Arc()).build();
kpeter@334:     }
kpeter@334: 
kpeter@334:     /// \brief The node on the given position.
kpeter@334:     ///
kpeter@334:     /// Gives back the node on the given position.
kpeter@334:     Node operator()(int i, int j) const {
kpeter@334:       return Parent::operator()(i, j);
kpeter@334:     }
kpeter@334: 
kpeter@334:     /// \brief Gives back the row index of the node.
kpeter@334:     ///
kpeter@334:     /// Gives back the row index of the node.
kpeter@334:     int row(Node n) const {
kpeter@334:       return Parent::row(n);
kpeter@334:     }
kpeter@334: 
kpeter@334:     /// \brief Gives back the column index of the node.
kpeter@334:     ///
kpeter@334:     /// Gives back the column index of the node.
kpeter@334:     int col(Node n) const {
kpeter@334:       return Parent::col(n);
kpeter@334:     }
kpeter@334: 
kpeter@334:     /// \brief Gives back the width of the grid.
kpeter@334:     ///
kpeter@334:     /// Gives back the width of the grid.
kpeter@334:     int width() const {
kpeter@334:       return Parent::width();
kpeter@334:     }
kpeter@334: 
kpeter@334:     /// \brief Gives back the height of the grid.
kpeter@334:     ///
kpeter@334:     /// Gives back the height of the grid.
kpeter@334:     int height() const {
kpeter@334:       return Parent::height();
kpeter@334:     }
kpeter@334: 
kpeter@334:     /// \brief Gives back the arc goes down from the node.
kpeter@334:     ///
kpeter@334:     /// Gives back the arc goes down from the node. If there is not
kpeter@334:     /// outgoing arc then it gives back \c INVALID.
kpeter@334:     Arc down(Node n) const {
kpeter@334:       Edge e = _down(n);
kpeter@334:       return e != INVALID ? direct(e, true) : INVALID;
kpeter@334:     }
kpeter@334: 
kpeter@334:     /// \brief Gives back the arc goes up from the node.
kpeter@334:     ///
kpeter@334:     /// Gives back the arc goes up from the node. If there is not
kpeter@334:     /// outgoing arc then it gives back \c INVALID.
kpeter@334:     Arc up(Node n) const {
kpeter@334:       Edge e = _up(n);
kpeter@334:       return e != INVALID ? direct(e, false) : INVALID;
kpeter@334:     }
kpeter@334: 
kpeter@334:     /// \brief Gives back the arc goes right from the node.
kpeter@334:     ///
kpeter@334:     /// Gives back the arc goes right from the node. If there is not
kpeter@334:     /// outgoing arc then it gives back \c INVALID.
kpeter@334:     Arc right(Node n) const {
kpeter@334:       Edge e = _right(n);
kpeter@334:       return e != INVALID ? direct(e, true) : INVALID;
kpeter@334:     }
kpeter@334: 
kpeter@334:     /// \brief Gives back the arc goes left from the node.
kpeter@334:     ///
kpeter@334:     /// Gives back the arc goes left from the node. If there is not
kpeter@334:     /// outgoing arc then it gives back \c INVALID.
kpeter@334:     Arc left(Node n) const {
kpeter@334:       Edge e = _left(n);
kpeter@334:       return e != INVALID ? direct(e, false) : INVALID;
kpeter@334:     }
kpeter@334: 
kpeter@334:   }; // class GridGraph
kpeter@334: 
kpeter@334:   /// \brief Index map of the grid graph
kpeter@334:   ///
kpeter@334:   /// Just returns an IndexMap for the grid graph.
kpeter@334:   inline GridGraph::IndexMap indexMap(const GridGraph& graph) {
kpeter@334:     return GridGraph::IndexMap(graph);
kpeter@334:   }
kpeter@334: 
kpeter@334:   /// \brief Row map of the grid graph
kpeter@334:   ///
kpeter@334:   /// Just returns a RowMap for the grid graph.
kpeter@334:   inline GridGraph::RowMap rowMap(const GridGraph& graph) {
kpeter@334:     return GridGraph::RowMap(graph);
kpeter@334:   }
kpeter@334: 
kpeter@334:   /// \brief Column map of the grid graph
kpeter@334:   ///
kpeter@334:   /// Just returns a ColMap for the grid graph.
kpeter@334:   inline GridGraph::ColMap colMap(const GridGraph& graph) {
kpeter@334:     return GridGraph::ColMap(graph);
kpeter@334:   }
kpeter@334: }
kpeter@334: 
kpeter@334: #endif // GRID_GRAPH_H