/// <summary>
/// 添加弧
/// </summary>
/// <param name="arcNode"></param>
/// <param name="fromData"></param>
/// <param name="toData"></param>
/// <returns></returns>
public bool addArcNode(ArcNode arcNode, object fromData, object toData)
{
// if(vertices.Contains(from)==false||vertices.Contains(to)==false)
// {
// //添加弧时要保证弧所连接的两个顶点要存在
// return false;
// }
//添加弧时要保证弧所连接的两个顶点要存在
VNode from = addVNode(fromData);
VNode to = addVNode(toData);
//保证从一个顶点到另一个顶点只有一条弧
ArcNode arc = from.firstarc;
for (; arc != null; arc = arc.nextarc)
{
if (arc.adjvex == to)
{
return(false); //已经存在一条从顶点from到顶点to的弧
}
}
//将弧添加到图中
//如果这是从该顶点出发的第一条弧
if (from.firstarc == null)
{
from.firstarc = from.endarc = arcNode;
}
else
{
//不是第一条弧
from.endarc.nextarc = arcNode;
from.endarc = arcNode;
}
arcNode.adjvex = to;
to.inDegree++;
from.outDegree++;
return(true);
}
/// <summary>
/// 拓扑排序
/// </summary>
/// <returns>返回输出顶点数组</returns>
public ArrayList topSort()
{
Stack stack = new Stack(startSize);
ArrayList list = new ArrayList(startSize);
// 将当前所有入度为零的顶点入栈
for (int i = 0; i < vertices.Count; i++)
{
VNode node = (VNode)vertices[i];
if (node.inDegree == 0)
{
stack.Push(node);
}
}
while (stack.Count != 0)
{
VNode v = (VNode)stack.Pop();
// 输出无前驱的顶点
list.Add(v.data);
ArcNode arc = v.firstarc;
//遍历依附于该顶点的所有弧
for (; arc != null; arc = arc.nextarc)
{
//所有邻接点的入度减1
arc.adjvex.inDegree--;
if (arc.adjvex.inDegree == 0)
{
//新的无前驱的顶点
stack.Push(arc.adjvex);
}
}
}
return(list);
}
