1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/lemon/grid_graph.h Thu Aug 11 13:20:52 2005 +0000
1.3 @@ -0,0 +1,320 @@
1.4 +/* -*- C++ -*-
1.5 + * lemon/grid_graph.h - Part of LEMON, a generic C++ optimization library
1.6 + *
1.7 + * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
1.8 + * (Egervary Research Group on Combinatorial Optimization, EGRES).
1.9 + *
1.10 + * Permission to use, modify and distribute this software is granted
1.11 + * provided that this copyright notice appears in all copies. For
1.12 + * precise terms see the accompanying LICENSE file.
1.13 + *
1.14 + * This software is provided "AS IS" with no warranty of any kind,
1.15 + * express or implied, and with no claim as to its suitability for any
1.16 + * purpose.
1.17 + *
1.18 + */
1.19 +
1.20 +#ifndef GRID_GRAPH_H
1.21 +#define GRID_GRAPH_H
1.22 +
1.23 +#include <iostream>
1.24 +#include <lemon/invalid.h>
1.25 +#include <lemon/utility.h>
1.26 +
1.27 +#include <lemon/bits/iterable_graph_extender.h>
1.28 +#include <lemon/bits/alteration_notifier.h>
1.29 +#include <lemon/bits/default_map.h>
1.30 +
1.31 +#include <lemon/bits/undir_graph_extender.h>
1.32 +
1.33 +namespace lemon {
1.34 +
1.35 + class GridGraphBase {
1.36 +
1.37 + public:
1.38 +
1.39 + typedef GridGraphBase Graph;
1.40 +
1.41 + class Node;
1.42 + class Edge;
1.43 +
1.44 + public:
1.45 +
1.46 + GridGraphBase() {}
1.47 +
1.48 + protected:
1.49 +
1.50 + /// \brief Creates a grid graph with the given size.
1.51 + ///
1.52 + /// Creates a grid graph with the given size.
1.53 + void construct(int height, int width) {
1.54 + _height = height; _width = width;
1.55 + _nodeNum = height * width; _edgeNum = 2 * _nodeNum - width - height;
1.56 + _edgeLimit = _nodeNum - width;
1.57 + }
1.58 +
1.59 + public:
1.60 +
1.61 + /// \brief The node on the given position.
1.62 + ///
1.63 + /// Gives back the node on the given position.
1.64 + Node operator()(int i, int j) const {
1.65 + return Node(i * _width + j);
1.66 + }
1.67 +
1.68 + /// \brief Gives back the row index of the node.
1.69 + ///
1.70 + /// Gives back the row index of the node.
1.71 + int row(Node n) const {
1.72 + return n.id / _width;
1.73 + }
1.74 +
1.75 + /// \brief Gives back the coloumn index of the node.
1.76 + ///
1.77 + /// Gives back the coloumn index of the node.
1.78 + int col(Node node) const {
1.79 + return n.id % _width;
1.80 + }
1.81 +
1.82 + /// \brief Gives back the width of the graph.
1.83 + ///
1.84 + /// Gives back the width of the graph.
1.85 + int width() const {
1.86 + return _width;
1.87 + }
1.88 +
1.89 + /// \brief Gives back the height of the graph.
1.90 + ///
1.91 + /// Gives back the height of the graph.
1.92 + int height() const {
1.93 + return _height;
1.94 + }
1.95 +
1.96 + typedef True NodeNumTag;
1.97 + typedef True EdgeNumTag;
1.98 +
1.99 + ///Number of nodes.
1.100 + int nodeNum() const { return _nodeNum; }
1.101 + ///Number of edges.
1.102 + int edgeNum() const { return _edgeNum; }
1.103 +
1.104 + /// Maximum node ID.
1.105 +
1.106 + /// Maximum node ID.
1.107 + ///\sa id(Node)
1.108 + int maxId(Node = INVALID) const { return nodeNum() - 1; }
1.109 + /// Maximum edge ID.
1.110 +
1.111 + /// Maximum edge ID.
1.112 + ///\sa id(Edge)
1.113 + int maxId(Edge = INVALID) const { return edgeNum() - 1; }
1.114 +
1.115 + /// \brief Gives back the source node of an edge.
1.116 + ///
1.117 + /// Gives back the source node of an edge.
1.118 + Node source(Edge e) const {
1.119 + if (e.id < _edgeLimit) {
1.120 + return e.id;
1.121 + } else {
1.122 + return (e.id - _edgeLimit) % (_width - 1) +
1.123 + (e.id - _edgeLimit) / (_width - 1) * _width;
1.124 + }
1.125 + }
1.126 +
1.127 + /// \brief Gives back the target node of an edge.
1.128 + ///
1.129 + /// Gives back the target node of an edge.
1.130 + Node target(Edge e) const {
1.131 + if (e.id < _edgeLimit) {
1.132 + return e.id + _width;
1.133 + } else {
1.134 + return (e.id - _edgeLimit) % (_width - 1) +
1.135 + (e.id - _edgeLimit) / (_width - 1) * _width + 1;
1.136 + }
1.137 + }
1.138 +
1.139 + /// Node ID.
1.140 +
1.141 + /// The ID of a valid Node is a nonnegative integer not greater than
1.142 + /// \ref maxNodeId(). The range of the ID's is not surely continuous
1.143 + /// and the greatest node ID can be actually less then \ref maxNodeId().
1.144 + ///
1.145 + /// The ID of the \ref INVALID node is -1.
1.146 + ///\return The ID of the node \c v.
1.147 +
1.148 + static int id(Node v) { return v.id; }
1.149 + /// Edge ID.
1.150 +
1.151 + /// The ID of a valid Edge is a nonnegative integer not greater than
1.152 + /// \ref maxEdgeId(). The range of the ID's is not surely continuous
1.153 + /// and the greatest edge ID can be actually less then \ref maxEdgeId().
1.154 + ///
1.155 + /// The ID of the \ref INVALID edge is -1.
1.156 + ///\return The ID of the edge \c e.
1.157 + static int id(Edge e) { return e.id; }
1.158 +
1.159 + static Node fromId(int id, Node) { return Node(id);}
1.160 +
1.161 + static Edge fromId(int id, Edge) { return Edge(id);}
1.162 +
1.163 + typedef True FindEdgeTag;
1.164 +
1.165 + /// Finds an edge between two nodes.
1.166 +
1.167 + /// Finds an edge from node \c u to node \c v.
1.168 + ///
1.169 + /// If \c prev is \ref INVALID (this is the default value), then
1.170 + /// It finds the first edge from \c u to \c v. Otherwise it looks for
1.171 + /// the next edge from \c u to \c v after \c prev.
1.172 + /// \return The found edge or INVALID if there is no such an edge.
1.173 + Edge findEdge(Node u, Node v, Edge prev = INVALID) {
1.174 + if (prev != INVALID) return INVALID;
1.175 + if (v.id - u.id == _width) return Edge(u.id);
1.176 + if (v.id - u.id == 1 && u.id % _width < _width - 1) {
1.177 + return Edge(u.id / _width * (_width - 1) +
1.178 + u.id % _width + _edgeLimit);
1.179 + }
1.180 + return INVALID;
1.181 + }
1.182 +
1.183 +
1.184 + class Node {
1.185 + friend class GridGraphBase;
1.186 +
1.187 + protected:
1.188 + int id;
1.189 + Node(int _id) { id = _id;}
1.190 + public:
1.191 + Node() {}
1.192 + Node (Invalid) { id = -1; }
1.193 + bool operator==(const Node node) const {return id == node.id;}
1.194 + bool operator!=(const Node node) const {return id != node.id;}
1.195 + bool operator<(const Node node) const {return id < node.id;}
1.196 + };
1.197 +
1.198 +
1.199 +
1.200 + class Edge {
1.201 + friend class GridGraphBase;
1.202 +
1.203 + protected:
1.204 + int id;
1.205 +
1.206 + Edge(int _id) : id(_id) {}
1.207 +
1.208 + public:
1.209 + Edge() { }
1.210 + Edge (Invalid) { id = -1; }
1.211 + bool operator==(const Edge edge) const {return id == edge.id;}
1.212 + bool operator!=(const Edge edge) const {return id != edge.id;}
1.213 + bool operator<(const Edge edge) const {return id < edge.id;}
1.214 + };
1.215 +
1.216 + void first(Node& node) const {
1.217 + node.id = nodeNum() - 1;
1.218 + }
1.219 +
1.220 + static void next(Node& node) {
1.221 + --node.id;
1.222 + }
1.223 +
1.224 + void first(Edge& edge) const {
1.225 + edge.id = edgeNum() - 1;
1.226 + }
1.227 +
1.228 + static void next(Edge& edge) {
1.229 + --edge.id;
1.230 + }
1.231 +
1.232 + void firstOut(Edge& edge, const Node& node) const {
1.233 + if (node.id < _nodeNum - _width) {
1.234 + edge.id = node.id;
1.235 + } else if (node.id % _width < _width - 1) {
1.236 + edge.id = _edgeLimit + node.id % _width +
1.237 + (node.id / _width) * (_width - 1);
1.238 + } else {
1.239 + edge.id = -1;
1.240 + }
1.241 + }
1.242 +
1.243 + void nextOut(Edge& edge) const {
1.244 + if (edge.id >= _edgeLimit) {
1.245 + edge.id = -1;
1.246 + } else if (edge.id % _width < _width - 1) {
1.247 + edge.id = _edgeLimit + edge.id % _width +
1.248 + (edge.id / _width) * (_width - 1);
1.249 + } else {
1.250 + edge.id = -1;
1.251 + }
1.252 + }
1.253 +
1.254 + void firstIn(Edge& edge, const Node& node) const {
1.255 + if (node.id >= _width) {
1.256 + edge.id = node.id - _width;
1.257 + } else if (node.id % _width > 0) {
1.258 + edge.id = _edgeLimit + node.id % _width +
1.259 + (node.id / _width) * (_width - 1) - 1;
1.260 + } else {
1.261 + edge.id = -1;
1.262 + }
1.263 + }
1.264 +
1.265 + void nextIn(Edge& edge) const {
1.266 + if (edge.id >= _edgeLimit) {
1.267 + edge.id = -1;
1.268 + } else if (edge.id % _width > 0) {
1.269 + edge.id = _edgeLimit + edge.id % _width +
1.270 + (edge.id / _width + 1) * (_width - 1) - 1;
1.271 + } else {
1.272 + edge.id = -1;
1.273 + }
1.274 + }
1.275 +
1.276 + private:
1.277 + int _width, _height;
1.278 + int _nodeNum, _edgeNum;
1.279 + int _edgeLimit;
1.280 + };
1.281 +
1.282 +
1.283 + typedef UndirGraphExtender<GridGraphBase>
1.284 + UndirGridGraphBase;
1.285 + typedef AlterableUndirGraphExtender<UndirGridGraphBase>
1.286 + AlterableGridGraphBase;
1.287 + typedef IterableUndirGraphExtender<AlterableGridGraphBase>
1.288 + IterableGridGraphBase;
1.289 + typedef MappableUndirGraphExtender<IterableGridGraphBase>
1.290 + MappableGridGraphBase;
1.291 +
1.292 + /// \ingroup graphs
1.293 + ///
1.294 + /// \brief Grid graph class
1.295 + ///
1.296 + /// This class implements a special graph type. The nodes of the
1.297 + /// graph can be indiced by two integer \c (i,j) value where \c i
1.298 + /// is in the \c [0,height) range and j is in the [0, width) range.
1.299 + /// Two nodes are connected in the graph if the indices differ only
1.300 + /// on one position and only one is the difference.
1.301 + ///
1.302 + /// The graph can be indiced in the following way:
1.303 + /// \code
1.304 + /// GridGraph graph(h, w);
1.305 + /// GridGraph::NodeMap<int> val(graph);
1.306 + /// for (int i = 0; i < graph.height(); ++i) {
1.307 + /// for (int j = 0; j < graph.width(); ++j) {
1.308 + /// val[graph(i, j)] = i + j;
1.309 + /// }
1.310 + /// }
1.311 + /// \endcode
1.312 + ///
1.313 + /// The graph type is fully conform to the \ref concept::UndirGraph
1.314 + /// "Undirected Graph" concept.
1.315 + ///
1.316 + /// \author Balazs Dezso
1.317 + class GridGraph : public MappableGridGraphBase {
1.318 + public:
1.319 +
1.320 + GridGraph(int m, int n) { construct(m, n); }
1.321 + };
1.322 +}
1.323 +#endif