//从PlanCourse取出一个当前累积权值最小并没有被处理过的节点
public static Node GetMinWeightRouteNode(PlanCourse planCourse, List <Node> NodeList, string OriginID)
{
double minWeight = double.MaxValue;
Node destNode = null;
foreach (Node node in NodeList)
{
if (node.ID == OriginID)
{
continue;
}
PassedPath pPath = planCourse[node.ID]; //寻找出节点的最短路径
if (pPath.BeProcessed)
{
continue;
}
if (pPath.SumWeight < minWeight)
{
minWeight = pPath.SumWeight;
destNode = node;
}
}
return(destNode);
}
//获取从起点到终点的权值最小的路径，DIJSTRA算法
public PlanCourse Plan(List <Node> NodeList, string OriginID)
{
//获取源点到与其相邻点的路径和权重值
PlanCourse planCourse = new PlanCourse(NodeList, OriginID);
//获取当前累积权重值最小，并且没有被处理过的节点
Node curNode = GetMinWeightRouteNode(planCourse, NodeList, OriginID);
while (curNode != null)
{
PassedPath curPath = planCourse[curNode.ID];
foreach (Edge edge in curNode.EdgeList)
{
if (edge.EndNodeID != OriginID)
{
PassedPath targetPath = planCourse[edge.EndNodeID];
double tempWeight = curPath.SumWeight + edge.Weight;
if (tempWeight < targetPath.SumWeight)
{
targetPath.SumWeight = tempWeight;
targetPath.PathIDList.Clear();
for (int i = 0; i < curPath.PathIDList.Count; i++)
{
targetPath.PathIDList.Add(curPath.PathIDList[i].ToString());
}
targetPath.PathIDList.Add(curNode.ID);
}
}
}
//标记该节点已经处理了
planCourse[curNode.ID].BeProcessed = true;
///获取下一个累积权重值最小，并且没有被处理过的节点
curNode = GetMinWeightRouteNode(planCourse, NodeList, OriginID);
}
PlanCourse resultplancourse = planCourse;
return(resultplancourse);
//RoutePlanResult[] result = new RoutePlanResult[DestID.Length];
//for (int i = 0; i < DestID.Length; i++)
//{
// if (!DestID[i].Equals(OriginID))
// {
// result[i] = GetResult(planCourse, DestID[i]);
// }
// else
// {
// string[] passedNodeID = new string[1];
// passedNodeID[0] = DestID[i];
// result[i] = new RoutePlanResult(passedNodeID, 0);
// }
//}
//return result;
//return GetResult(planCourse,DestID);
}
private void InitializeWeight(Node OriginNode)
{
if ((OriginNode.EdgeList == null) || (OriginNode.EdgeList.Count == 0))
{
return;
}
foreach (Edge edge in OriginNode.EdgeList)
{
PassedPath pPath = (PassedPath)htPassedPath[edge.EndNodeID];
if (pPath == null)
{
continue;
}
pPath.PathIDList.Add(OriginNode.ID);
pPath.SumWeight = edge.Weight;
}
}
public static RoutePlanResult GetResult(PlanCourse planCourse, string destID)
{
PassedPath pPath = planCourse[destID];
if (pPath.SumWeight == double.MaxValue)
{
RoutePlanResult routePlanResult = new RoutePlanResult(null, double.MaxValue);
return(routePlanResult);
}
string[] passedNodeIDs = new string[pPath.PathIDList.Count];
for (int i = 0; i < passedNodeIDs.Length; i++)
{
passedNodeIDs[i] = pPath.PathIDList[i].ToString();
}
RoutePlanResult result = new RoutePlanResult(passedNodeIDs, pPath.SumWeight);
return(result);
}
//获取权值最小的路径，DIJISTRA算法
public RoutePlanResult Plan(List <Node> nodeList, string originID, string destID)
{
PlanCourse planCourse = new PlanCourse(nodeList, originID); //获得源点到与其相邻点的路径和权值
Node curNode = GetMinWeightRouteNode(planCourse, nodeList, originID); //当前累积权值最小，并且没有被处理过的节点
while (curNode != null)
{
PassedPath curPath = planCourse[curNode.ID];
foreach (Edge edge in curNode.EdgeList)
{
if (edge.EndNodeID != originID)
{
PassedPath targetPath = planCourse[edge.EndNodeID];//选取没有被处理并且当前累积权值最小的节点TargetNode
double tempWeight = curPath.SumWeight + edge.Weight;
if (tempWeight < targetPath.SumWeight)
{
targetPath.SumWeight = tempWeight; //以此点为终点的路径长度
targetPath.PathIDList.Clear(); //将之前的路径清空
for (int i = 0; i < curPath.PathIDList.Count; i++)
{
targetPath.PathIDList.Add(curPath.PathIDList[i].ToString());
}
targetPath.PathIDList.Add(curNode.ID);
}
}
}
//标志为已处理
planCourse[curNode.ID].BeProcessed = true;
//获取下一个未处理节点
curNode = GetMinWeightRouteNode(planCourse, nodeList, originID);
}
//表示规划结束
return(GetResult(planCourse, destID));
}
public Hashtable htPassedPath;//定义一个哈希表存储各节点的路径表
public PlanCourse(List <Node> NodeList, string OriginID)
{
htPassedPath = new Hashtable();
Node OriginNode = null;
foreach (Node node in NodeList)
{
if (node.ID == OriginID)
{
OriginNode = node;
}
else
{
PassedPath pPath = new PassedPath(node.ID);
htPassedPath.Add(node.ID, pPath);
}
if (OriginNode == null)
{
continue;
}
}
InitializeWeight(OriginNode);
}