/// <summary>
/// 向加权有向图中添加一条边e
/// </summary>
/// <param name="e"></param>
public void addEdge(EdgeDirected e)
{
// 边e是有方向的，所以只需要让e出现在起点的邻接表中即可
int v = e.from();
this.adjQueue[v].enqueue(e);
this.E++;
}
/// <summary>
/// 最短路径
/// </summary>
private static void DijksraSPTest()
{
// 创建加权有向图
EdgeDirectedWeightedDirgraph graph = new EdgeDirectedWeightedDirgraph(8);
graph.addEdge(new EdgeDirected(4, 5, 0.35f));
graph.addEdge(new EdgeDirected(5, 4, 0.35f));
graph.addEdge(new EdgeDirected(4, 7, 0.37f));
graph.addEdge(new EdgeDirected(5, 7, 0.28f));
graph.addEdge(new EdgeDirected(7, 5, 0.28f));
graph.addEdge(new EdgeDirected(5, 1, 0.32f));
graph.addEdge(new EdgeDirected(0, 4, 0.38f));
graph.addEdge(new EdgeDirected(0, 2, 0.26f));
graph.addEdge(new EdgeDirected(7, 3, 0.39f));
graph.addEdge(new EdgeDirected(1, 3, 0.29f));
graph.addEdge(new EdgeDirected(2, 7, 0.34f));
graph.addEdge(new EdgeDirected(6, 2, 0.40f));
graph.addEdge(new EdgeDirected(3, 6, 0.52f));
graph.addEdge(new EdgeDirected(6, 0, 0.58f));
graph.addEdge(new EdgeDirected(6, 4, 0.93f));
// 创建 DijksraSP 对象 查找最短路径
int start = 0;
DijksraSP dijksra = new DijksraSP(graph, start);
// 查找最短路径 0->6
int end = 6;
QueueList <EdgeDirected> allEdges = dijksra.pathTo(end);
// 遍历打印
if (allEdges == null)
{
Console.WriteLine("not path to " + end);
}
else
{
IEnumerator ie = allEdges.GetEnumerator();
while (ie.MoveNext())
{
EdgeDirected e = (EdgeDirected)ie.Current;
Console.WriteLine(e.from() + " -> " + e.to() + " : " + e.weight().ToString("F2"));
}
}
}
/// <summary>
/// 查询从起点s到顶点v的最短路径中所有的边
/// </summary>
/// <param name="v"></param>
/// <returns></returns>
public QueueList <EdgeDirected> pathTo(int v)
{
// 判断从顶点 s 到顶点v是否可达
if (!this.hasPathTo(v))
{
return(null);
}
// 创建队列对象
QueueList <EdgeDirected> allEdges = new QueueList <EdgeDirected>();
while (true)
{
EdgeDirected e = this.edgeTo[v];
if (e == null)
{
break;
}
allEdges.enqueue(e);
v = e.from();
}
return(allEdges);
}
