// Set a vertexe's value
public Boolean SetVertexValue(Guid vertexId, Int32 newValue)
{
if (!this.VertexExists(vertexId))
{
return(false);
}
UVertex uv = this.Vertices[vertexId];
uv.Value = newValue;
return(true);
}
// Add a vertex
public Boolean AddVertex(UVertex vertexToAdd)
{
if (VertexExists(vertexToAdd.VertexId) == true)
{
return(false);
}
this.Vertices.Add(vertexToAdd.VertexId, vertexToAdd);
this.AdjacencyMatrix.Add(vertexToAdd.VertexId, new List <Guid>());
this.IncidenceMatrix.Add(vertexToAdd.VertexId, new List <Guid>());
return(true);
}
//private static readonly GraphUtils instance = new GraphUtils();
/// <summary>
///
/// </summary>
//private GraphUtils()
//{
//}
/// <summary>
///
/// </summary>
//public static GraphUtils Instance
//{
// get
// {
// return instance;
// }
//}
/// <summary>
///
/// </summary>
/// <param name="appContext"></param>
/// <returns></returns>
public static UGraph GenerateRandomGraph(AppContext appContext)
{
Int32 numNodes = appContext.RandomSource.Next(Defines.MIN_NUM_NODES, Defines.MAX_NUM_NODES);
//appContext.CurrentGraph = new UGraph();
UGraph outGraph = new UGraph();
//appContext.CurrentGraphState = GraphState.New;
for (Int32 i = 0; i < numNodes; i++)
{
UVertex uv = new UVertex
{
Value = appContext.RandomSource.Next()
};
outGraph.AddVertex(uv);
}
foreach (KeyValuePair <Guid, UVertex> kvp1 in outGraph.Vertices)
{
foreach (KeyValuePair <Guid, UVertex> kvp2 in outGraph.Vertices)
{
if (kvp1.Value.VertexId != kvp2.Value.VertexId)
{
Int32 prob = appContext.RandomSource.Next(1, 10);
if (prob >= Defines.EDGE_PROBABILITY * 10)
{
UEdge ue = new UEdge
{
HeadVertexId = kvp1.Value.VertexId,
TailVertexId = kvp2.Value.VertexId,
Value = appContext.RandomSource.Next()
};
outGraph.Edges.Add(ue.EdgeId, ue);
kvp1.Value.AddNeighbor(kvp2.Value.VertexId);
kvp1.Value.AddEdge(ue.EdgeId);
kvp2.Value.AddNeighbor(kvp1.Value.VertexId);
kvp2.Value.AddEdge(ue.EdgeId);
}
}
}
}
return(outGraph);
}
//public int VertexCount => this.Vertices.Count;
//public int EdgeCount => this.Edges.Count;
// adjacent: whether there is an edge from vertex x to vertex y
public Boolean Adjacent(Guid headVertexId, Guid tailVertexId)
{
if (this.Vertices.ContainsKey(headVertexId) == false)
{
return(false);
}
UVertex uv = this.Vertices[headVertexId];
foreach (Guid neighId in uv.Neighbors)
{
if (neighId == tailVertexId)
{
return(true);
}
}
return(false);
}
// neighbors: list all neighbors of a given vertex.
public List <Guid> Neighbors(Guid vertexId)
{
UVertex uv = this.Vertices[vertexId];
return(uv.Neighbors);
}