1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/lemon/topology.h Mon Oct 03 10:18:38 2005 +0000
1.3 @@ -0,0 +1,219 @@
1.4 +/* -*- C++ -*-
1.5 + * lemon/topology.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 LEMON_TOPOLOGY_H
1.21 +#define LEMON_TOPOLOGY_H
1.22 +
1.23 +#include <lemon/dfs.h>
1.24 +#include <lemon/graph_utils.h>
1.25 +
1.26 +#include <lemon/concept/graph.h>
1.27 +#include <lemon/concept/undir_graph.h>
1.28 +#include <lemon/concept_check.h>
1.29 +
1.30 +/// \ingroup flowalgs
1.31 +/// \file
1.32 +/// \brief Topology related algorithms
1.33 +///
1.34 +/// Topology related algorithms
1.35 +
1.36 +namespace lemon {
1.37 +
1.38 + namespace _topology_bits {
1.39 +
1.40 + template <typename NodeMap>
1.41 + class BackCounterMap {
1.42 + public:
1.43 + BackCounterMap(NodeMap& _nodeMap, int _counter)
1.44 + : nodeMap(_nodeMap), counter(_counter) {}
1.45 +
1.46 + void set(typename NodeMap::Key key, bool val) {
1.47 + if (val) {
1.48 + nodeMap.set(key, --counter);
1.49 + } else {
1.50 + nodeMap.set(key, -1);
1.51 + }
1.52 + }
1.53 +
1.54 + bool operator[](typename NodeMap::Key key) const {
1.55 + return nodeMap[key] != -1;
1.56 + }
1.57 +
1.58 + private:
1.59 + NodeMap& nodeMap;
1.60 + int counter;
1.61 + };
1.62 + }
1.63 +
1.64 + // \todo Its to special output // ReadWriteMap
1.65 + template <typename Graph, typename NodeMap>
1.66 + bool topological_sort(const Graph& graph, NodeMap& nodeMap) {
1.67 + using namespace _topology_bits;
1.68 +
1.69 + checkConcept<concept::StaticGraph, Graph>();
1.70 + checkConcept<concept::ReadWriteMap<typename Graph::Node, int>, NodeMap>();
1.71 +
1.72 + typedef typename Graph::Node Node;
1.73 + typedef typename Graph::NodeIt NodeIt;
1.74 + typedef typename Graph::Edge Edge;
1.75 +
1.76 + typedef BackCounterMap<NodeMap> ProcessedMap;
1.77 +
1.78 + typename Dfs<Graph>::template DefProcessedMap<ProcessedMap>::
1.79 + Dfs dfs(graph);
1.80 +
1.81 + ProcessedMap processed(nodeMap, countNodes(graph));
1.82 +
1.83 + dfs.processedMap(processed);
1.84 + dfs.init();
1.85 + for (NodeIt it(graph); it != INVALID; ++it) {
1.86 + if (!dfs.reached(it)) {
1.87 + dfs.addSource(it);
1.88 + while (!dfs.emptyQueue()) {
1.89 + Edge edge = dfs.nextEdge();
1.90 + Node target = graph.target(edge);
1.91 + if (dfs.reached(target) && !processed[target]) {
1.92 + return false;
1.93 + }
1.94 + dfs.processNextEdge();
1.95 + }
1.96 + }
1.97 + }
1.98 + return true;
1.99 + }
1.100 +
1.101 + /// \brief Check that the given graph is a DAG.
1.102 + ///
1.103 + /// Check that the given graph is a DAG. The DAG is
1.104 + /// an Directed Acyclic Graph.
1.105 + template <typename Graph>
1.106 + bool dag(const Graph& graph) {
1.107 +
1.108 + checkConcept<concept::StaticGraph, Graph>();
1.109 +
1.110 + typedef typename Graph::Node Node;
1.111 + typedef typename Graph::NodeIt NodeIt;
1.112 + typedef typename Graph::Edge Edge;
1.113 +
1.114 + typedef typename Graph::template NodeMap<bool> ProcessedMap;
1.115 +
1.116 + typename Dfs<Graph>::template DefProcessedMap<ProcessedMap>::
1.117 + Dfs dfs(graph);
1.118 +
1.119 + ProcessedMap processed(graph);
1.120 + dfs.processedMap(processed);
1.121 +
1.122 + dfs.init();
1.123 + for (NodeIt it(graph); it != INVALID; ++it) {
1.124 + if (!dfs.reached(it)) {
1.125 + dfs.addSource(it);
1.126 + while (!dfs.emptyQueue()) {
1.127 + Edge edge = dfs.nextEdge();
1.128 + Node target = graph.target(edge);
1.129 + if (dfs.reached(target) && !processed[target]) {
1.130 + return false;
1.131 + }
1.132 + dfs.processNextEdge();
1.133 + }
1.134 + }
1.135 + }
1.136 + return true;
1.137 + }
1.138 +
1.139 + // UndirGraph algorithms
1.140 +
1.141 + /// \brief Check that the given undirected graph is connected.
1.142 + ///
1.143 + /// Check that the given undirected graph connected.
1.144 + template <typename UndirGraph>
1.145 + bool connected(const UndirGraph& graph) {
1.146 + checkConcept<concept::UndirGraph, UndirGraph>();
1.147 + typedef typename UndirGraph::NodeIt NodeIt;
1.148 + if (NodeIt(graph) == INVALID) return false;
1.149 + Dfs<UndirGraph> dfs(graph);
1.150 + dfs.run(NodeIt(graph));
1.151 + for (NodeIt it(graph); it != INVALID; ++it) {
1.152 + if (!dfs.reached(it)) {
1.153 + return false;
1.154 + }
1.155 + }
1.156 + return true;
1.157 + }
1.158 +
1.159 + /// \brief Check that the given undirected graph is acyclic.
1.160 + ///
1.161 + /// Check that the given undirected graph acyclic.
1.162 + template <typename UndirGraph>
1.163 + bool acyclic(const UndirGraph& graph) {
1.164 + checkConcept<concept::UndirGraph, UndirGraph>();
1.165 + typedef typename UndirGraph::Node Node;
1.166 + typedef typename UndirGraph::NodeIt NodeIt;
1.167 + typedef typename UndirGraph::Edge Edge;
1.168 + Dfs<UndirGraph> dfs(graph);
1.169 + dfs.init();
1.170 + for (NodeIt it(graph); it != INVALID; ++it) {
1.171 + if (!dfs.reached(it)) {
1.172 + dfs.addSource(it);
1.173 + while (!dfs.emptyQueue()) {
1.174 + Edge edge = dfs.nextEdge();
1.175 + Node source = graph.source(edge);
1.176 + Node target = graph.target(edge);
1.177 + if (dfs.reached(target) &&
1.178 + dfs.pred(source) != graph.oppositeEdge(edge)) {
1.179 + return false;
1.180 + }
1.181 + dfs.processNextEdge();
1.182 + }
1.183 + }
1.184 + }
1.185 + return true;
1.186 + }
1.187 +
1.188 + /// \brief Check that the given undirected graph is tree.
1.189 + ///
1.190 + /// Check that the given undirected graph is tree.
1.191 + template <typename UndirGraph>
1.192 + bool tree(const UndirGraph& graph) {
1.193 + checkConcept<concept::UndirGraph, UndirGraph>();
1.194 + typedef typename UndirGraph::Node Node;
1.195 + typedef typename UndirGraph::NodeIt NodeIt;
1.196 + typedef typename UndirGraph::Edge Edge;
1.197 + if (NodeIt(graph) == INVALID) return false;
1.198 + Dfs<UndirGraph> dfs(graph);
1.199 + dfs.init();
1.200 + dfs.addSource(NodeIt(graph));
1.201 + while (!dfs.emptyQueue()) {
1.202 + Edge edge = dfs.nextEdge();
1.203 + Node source = graph.source(edge);
1.204 + Node target = graph.target(edge);
1.205 + if (dfs.reached(target) &&
1.206 + dfs.pred(source) != graph.oppositeEdge(edge)) {
1.207 + return false;
1.208 + }
1.209 + dfs.processNextEdge();
1.210 + }
1.211 + for (NodeIt it(graph); it != INVALID; ++it) {
1.212 + if (!dfs.reached(it)) {
1.213 + return false;
1.214 + }
1.215 + }
1.216 + return true;
1.217 + }
1.218 +
1.219 +
1.220 +} //namespace lemon
1.221 +
1.222 +#endif //LEMON_TOPOLOGY_H