/// <summary>
/// 单源最短路径会把一个点到其它所有点的最短路径算出来
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="graph"></param>
/// <param name="source"></param>
/// <param name="weightFuc"></param>
/// <returns></returns>
public static bool BellmanFord <T>(
this AdjacencyListGraph <T> graph,
AdjacencyVertex <T> source,
Func <AdjacencyListGraph <T>, AdjacencyVertex <T>, AdjacencyVertex <T>, int> weightFuc
) where T : IEquatable <T>
{
graph.InitializeSingleSource(source);
for (int i = 1; i <= graph.VertexLenght; i++)
{
foreach (var edge in graph.GetEdges())
{
graph.Relax(edge.Start, edge.End, weightFuc);
}
}
foreach (var edge in graph.GetEdges())
{
if (edge.Start.WeightBound >
Add(edge.End.WeightBound, weightFuc(graph, edge.Start, edge.End)))
{
return(false);
}
}
return(true);
}
/// <summary>
/// 单源最短路径会把一个点到其它所有点的最短路径算出来
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="graph"></param>
/// <param name="source"></param>
/// <param name="weightFuc"></param>
/// <returns></returns>
public static void Dijkstra <T>(
this AdjacencyListGraph <T> graph,
AdjacencyVertex <T> source,
Func <AdjacencyListGraph <T>, AdjacencyVertex <T>, AdjacencyVertex <T>, int> weightFuc
) where T : IEquatable <T>
{
graph.InitializeSingleSource(source);
var calcVertexs = new List <AdjacencyVertex <T> >();
var vertexs = graph.GetVertexs().ToList();
//不想再增加AdjacencyVertex对象的负担了
var queue = new ExtentionBinanyHeap <AdjacencyVertex <T> >
(
vertexs,
(first, second) =>
{
return(first.WeightBound < second.WeightBound);
}
);
// while (!queue.IsEmpty) 竟然把while写成if有才
while (!queue.IsEmpty)
{
var min = queue.Extract();
Console.WriteLine("calcVertex");
Console.WriteLine(min);
calcVertexs.Add(min);
var edges = graph.GetVertexEdge(min);
foreach (var edge in edges)
{
var oldWeight = edge.End.WeightBound;
Relax(graph, edge.Start, edge.End, weightFuc);
//没有索引位置一下让我傻逼了!网上找了一下也是有调整的。
if (oldWeight != edge.End.WeightBound)
{
queue.UpdateKey(edge.End, edge.End);
}
}
}
}
/// <summary>
/// 有向无回路图
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="graph"></param>
/// <param name="source"></param>
/// <param name="weightFuc"></param>
/// <returns></returns>
public static void DAGShortestPath <T>(
this AdjacencyListGraph <T> graph,
AdjacencyVertex <T> source,
Func <AdjacencyListGraph <T>, AdjacencyVertex <T>, AdjacencyVertex <T>, int> weightFuc
) where T : IEquatable <T>
{
graph.TopologicalSort();
graph.InitializeSingleSource(source);
var vertexs = graph.GetVertexs();
foreach (var orderVertex in vertexs)
{
var edges = graph.GetVertexEdge(orderVertex);
foreach (var edge in edges)
{
graph.Relax(edge.Start, edge.End, weightFuc);
}
}
}