Example #1
0
        public Graph.IGraphInterface GenerateGraph()
        {
            // Variable
            int probabilityEdge;

            foreach (Graph.IVertexInterface firstVertex in graph.AllVertices())
            {
                foreach (Graph.IVertexInterface secondVertex in graph.AllVertices())
                {
                    // No duplicates
                    if (usedVerticesHashSet.Contains(secondVertex))
                    {
                        continue;
                    }

                    if (firstVertex == secondVertex)
                    {
                        continue;
                    }

                    probabilityEdge = random.Next(0, 100000);

                    if (probabilityEdge <= probability)
                    {
                        graph.EdgeAdd(new Graph.Edge(firstVertex, secondVertex));
                    }
                }

                usedVerticesHashSet.Add(firstVertex);
            }

            usedVerticesHashSet = null;
            return(graph);
        }
Example #2
0
        /// <summary>
        /// Write a graph to a file
        /// If the graph is not initialized throws GraphInitializationException
        /// </summary>
        /// <param name="graph">graph</param>
        /// <returns>Is everything OK</returns>
        public bool WriteFile(Graph.IGraphInterface graph)
        {
            if (!graph.GetIsInitialized())
            {
                throw new MyException.GraphException.GraphInitializationException();
            }

            if (ExistsFile())
            {
                DeleteFile();
            }

            CreateFile();

            using (StreamWriter streamWriter = new StreamWriter(GetPath()))
            {
                // Header
                streamWriter.WriteLine(READERWRITERHEADER + Graph.Graph.GraphRepresentationEnum.adjacencyList);
                streamWriter.WriteLine(READERWRITERBALLAST);
                streamWriter.WriteLine(READERWRITERNAME + graph.GetName());
                streamWriter.WriteLine(READERWRITERCOUNTVERTICES + graph.GetRealCountVertices());
                streamWriter.WriteLine(READERWRITERBALLAST);

                // Graph
                streamWriter.WriteLine(READERWRITERGRAPH);

                foreach (Graph.Vertex vertex in graph.AllVertices())
                {
                    streamWriter.WriteLine(vertex.GetUserName());

                    foreach (Graph.Vertex neighbour in graph.Neighbours(vertex))
                    {
                        streamWriter.WriteLine(LEFTSEPARATORADJACENCYLIST + neighbour.GetUserName() + RIGHTSEPARATORADJACENCYLIST);
                    }
                }

                // Colored graph
                streamWriter.WriteLine(READERWRITERBALLAST);
                streamWriter.Write(READERWRITERCOLOREDGRAPH);
            }

            return(true);
        }
Example #3
0
        /// <summary>
        /// Return true if a graph has been colored in polynomal time, otherwise false
        /// </summary>
        /// <param name="graph">graph</param>
        /// <returns>true if graph has been colored in polynomal time, otherwise false</returns>
        public static bool TryOptimalColorInPolynomalTime(Graph.IGraphInterface graph)
        {
            bool isColored;
            IGraphColoringAlgorithmInterface algorithm;
            List <Graph.IVertexInterface>    optimalVertexList;

            Graph.IColoredGraphInterface coloredGraph = graph.GetColoredGraph();

            coloredGraph.ResetColors();

            // If the graph is chordal => use PEO for coloring
            if (graph.GetGraphProperty().GetIsChordal())
            {
                optimalVertexList = graph.GetGraphProperty().GetPerfectEliminationOrdering();

                coloredGraph.GreedyColoring(optimalVertexList);
                isColored = coloredGraph.InitializeColoredGraph();

                if (!isColored)
                {
                    throw new MyException.GraphColoringAlgorithmException.AlgorithmGraphIsNotColored();
                }

                return(true);
            }

            switch (graph.GetGraphProperty().GetGraphClass())
            {
            case Graph.GraphClass.GraphClass.GraphClassEnum.bipartiteGraph:
                Tuple <List <Graph.IVertexInterface>, List <Graph.IVertexInterface> > partites = graph.GetGraphProperty().GetPartites();

                coloredGraph.GreedyColoring(partites.Item1.Concat(partites.Item2).ToList());
                isColored = coloredGraph.InitializeColoredGraph();

                if (!isColored)
                {
                    throw new MyException.GraphColoringAlgorithmException.AlgorithmGraphIsNotColored();
                }

                return(true);

            case Graph.GraphClass.GraphClass.GraphClassEnum.completeBipartiteGraph:
                algorithm = new SequenceAlgorithm.SmallestLastSequence.SmallestLastSequence(graph);

                algorithm.Color();

                return(true);

            case Graph.GraphClass.GraphClass.GraphClassEnum.completeGraph:
                coloredGraph.GreedyColoring(graph.AllVertices());
                isColored = coloredGraph.InitializeColoredGraph();

                if (!isColored)
                {
                    throw new MyException.GraphColoringAlgorithmException.AlgorithmGraphIsNotColored();
                }

                return(true);

            case Graph.GraphClass.GraphClass.GraphClassEnum.cycleGraph:
            case Graph.GraphClass.GraphClass.GraphClassEnum.treeGraph:
                algorithm = new SequenceAlgorithm.ConnectedSequential.ConnectedSequential(graph);

                algorithm.Color();

                return(true);
            }

            return(false);
        }