/// <summary>
/// 从PlanCourse取出一个当前累积权值最小，并且没有被处理过的节点
/// </summary>
/// <returns></returns>
private Node GetMinWeightRudeNode(PlanCourse planCourse, List <Node> nodeList, string originID)
{
double weight = double.MaxValue;
Node destNode = null;
foreach (Node node in nodeList)
{
if (node.ID == originID)
{
continue;
}
PassedPath pPath = planCourse[node.ID];
if (pPath.BeProcessed)
{
continue;
}
if (pPath.Weight < weight)
{
weight = pPath.Weight;
destNode = node;
}
}
return(destNode);
}
public PlanCourse(List <Node> nodeList, string originID)
{
this.htPassedPath = new Hashtable();
Node originNode = null;
foreach (Node node in nodeList)
{
if (node.ID == originID)
{
originNode = node;
}
else
{
PassedPath pPath = new PassedPath(node.ID);
this.htPassedPath.Add(node.ID, pPath);
}
}
if (originNode == null)
{
throw new Exception("The origin node is not exist !");
}
this.InitializeWeight(originNode);
}
//获取权值最小的路径
public RoutePlanResult Paln(List <Node> nodeList, string originID, string destID)
{
//初始化起始节点到其他节点的路径表(权值，经过的节点，是否被处理）
//同时初始化其他节点的路径表
PlanCourse planCourse = new PlanCourse(nodeList, originID);
Node curNode = this.GetMinWeightRudeNode(planCourse, nodeList, originID);
#region 计算过程
while (curNode != null)
{
PassedPath curPath = planCourse[curNode.ID];
foreach (Edge edge in curNode.EdgeList)
{
if (edge.EndNodeID == originID)
{
continue;
}
PassedPath targetPath = planCourse[edge.EndNodeID];
double tempWeight = curPath.Weight + edge.Weight;
if (tempWeight < targetPath.Weight)
{
targetPath.Weight = tempWeight;
targetPath.PassedIDList.Clear();
for (int i = 0; i < curPath.PassedIDList.Count; i++)
{
targetPath.PassedIDList.Add(curPath.PassedIDList[i].ToString());
targetPath.PassedPointList.Add(curPath.PassedPointList[i]);
}
targetPath.PassedIDList.Add(curNode.ID);
targetPath.PassedPointList.Add(curNode.Point);
}
}
//标志为已处理
planCourse[curNode.ID].BeProcessed = true;
//获取下一个未处理节点
curNode = this.GetMinWeightRudeNode(planCourse, nodeList, originID);
}
#endregion
//表示规划结束
return(this.GetResult(planCourse, destID));
}
/// <summary>
/// 通过指定节点的边的权值初始化路径表
/// </summary>
/// <param name="originNode"></param>
private void InitializeWeight(Node originNode)
{
if ((originNode.EdgeList == null) || (originNode.EdgeList.Count == 0))
{
return;
}
foreach (Edge edge in originNode.EdgeList)
{
PassedPath pPath = this[edge.EndNodeID];
if (pPath == null)
{
continue;
}
pPath.PassedIDList.Add(originNode.ID);
pPath.PassedPointList.Add(originNode.Point);
pPath.Weight = edge.Weight;
}
}
/// <summary>
/// 从PlanCourse表中取出目标节点的PassedPath，这个PassedPath即是规划结果
/// </summary>
/// <returns></returns>
private RoutePlanResult GetResult(PlanCourse planCourse, string destID)
{
PassedPath pPath = planCourse[destID];
if (pPath.Weight == int.MaxValue)
{
RoutePlanResult result1 = new RoutePlanResult(null, int.MaxValue, null);
return(result1);
}
string[] passedNodeIDs = new string[pPath.PassedIDList.Count];
List <Point> passedlistPoint = new List <Point>();
for (int i = 0; i < passedNodeIDs.Length; i++)
{
passedNodeIDs[i] = pPath.PassedIDList[i].ToString();
passedlistPoint.Add(pPath.PassedPointList[i]);
}
RoutePlanResult result = new RoutePlanResult(passedNodeIDs, pPath.Weight, passedlistPoint);
return(result);
}