private void BFS(ALGraph G, int k)
{
int i;
Queue <int> Q;
EdgeNode p;
Q = new Queue <int>();
sb.Append(G.AdjList[k].vertex.ToString() + "--->");
visited[k] = true;
Q.Enqueue(k);
while (Q.Count != 0)
{
i = (int)Q.Dequeue();
p = G.AdjList[i].firstedge;
while (p != null)
{
if (!visited[p.adjvex])
{
sb.Append(G.AdjList[p.adjvex].vertex.ToString() + "--->");
visited[p.adjvex] = true;
Q.Enqueue(p.adjvex);
}
p = p.next;
}
}
}
/// <summary>
/// 应用程序的主入口点。
/// </summary>
static void Main1(string[] args)
{
int e;
int n;
Console.Write("请输入图的类型： 0 为无向图， 1 为有向图 ");
GraphType t = (GraphType)(int.Parse(Console.ReadLine()));
Console.Write("请输入图的顶点数 : ");
e = int.Parse(Console.ReadLine());
Console.Write("请输入图的边数（如果选择无向图，两接点间的边只需输入一次） : ");
n = int.Parse(Console.ReadLine());
ALGraph G = new ALGraph(e, n, t);
//构建一个有向图结构
(new GraphOperation()).CreateALGraph(G);
Console.Write("\n ");
//实现深度遍历
(new GraphOperation()).DFSTraverse(G);
Console.Write("\n ");
//实现广度遍历
(new GraphOperation()).BFSTraverse(G);
Console.Write("\n ");
//判断图的类型
(new GraphOperation()).NonPreFirstTopSort(G);
Console.ReadLine();
}
/// <summary>
/// 建全一个有向图对象
/// (不是建立 ^_^)
/// </summary>
/// <param name="G"></param>
public void CreateALGraph(ALGraph G)
{
int i, j, k;
EdgeNode s;
for (int vnc = 0; vnc < G.VertexNodeCount; vnc++)
{
VertexNode cuVN = new VertexNode();
Console.Write("请输入顶点的编号 : ");
cuVN.vertex = Console.ReadLine();
cuVN.firstedge = null;
G.AdjList[vnc] = cuVN;
}
for (k = 0; k < G.BordeCount; k++)
{
Console.Write("请输入边开始顶点的序号 : ");
i = int.Parse(Console.ReadLine()) - 1;
Console.Write("请输入边结束顶点的序号 : ");
j = int.Parse(Console.ReadLine()) - 1;
s = new EdgeNode();
s.adjvex = j;
s.next = G.AdjList[i].firstedge;
//邻接表头插法
G.AdjList[i].firstedge = s;
//建立无向图
if (G.theType == GraphType.UnDiGraph)
{
s = new EdgeNode();
s.adjvex = i;
s.next = G.AdjList[j].firstedge;
G.AdjList[j].firstedge = s;
}
}
}
private void DFS(ALGraph G, int i)
{
EdgeNode p;
sb.Append(G.AdjList[i].vertex.ToString() + "--->");
visited[i] = true;
p = G.AdjList[i].firstedge;
while (p != null)
{
if (!visited[p.adjvex])
{
DFS(G, p.adjvex);//递归
}
p = p.next;
}
}
/// <summary>
/// 深度优先遍历以邻接表表示的图G.
/// </summary>
/// <param name="G"></param>
public void DFSTraverse(ALGraph G)
{
visited = new bool[G.VertexNodeCount];
sb = new StringBuilder();
for (int i = 0; i < G.VertexNodeCount; i++)
{
visited[i] = false;
}
for (int i = 0; i < G.VertexNodeCount; i++)
{
if (!visited[i])
{
DFS(G, i);
}
}
Console.Write("深度优先遍历以邻接表表示的图G 的结果:\n ");
Console.Write(sb);
}
/// <summary>
/// 有向图无前驱的顶点优先之拓扑排序
/// </summary>
/// <param name="G"></param>
public void NonPreFirstTopSort(ALGraph G)
{
if (G.theType == GraphType.UnDiGraph)
{
Console.Write("对无向图进行拓扑排序是不对的!");
return;
}
StringBuilder SB = new StringBuilder();
int[] indegree = new int[G.VertexNodeCount];
Stack <int> S;
int i, j, count = 0;
EdgeNode p;
for (i = 0; i < G.VertexNodeCount; i++)
{
indegree[i] = 0;
}
for (i = 0; i < G.VertexNodeCount; i++)
{
for (p = G.AdjList[i].firstedge; p != null; p = p.next)
{
indegree[p.adjvex]++;
}
}
S = new Stack <int>();
for (i = 0; i < G.VertexNodeCount; i++)
{
if (indegree[i] == 0)
{
S.Push(i);
}
}
while (S.Count != 0)
{
i = (int)S.Pop();
SB.Append(G.AdjList[i].vertex.ToString() + "--->");
count++;
for (p = G.AdjList[i].firstedge; p != null; p = p.next)
{
j = p.adjvex;
indegree[j]--;
if (indegree[j] == 0)
{
S.Push(j);
}
}
}
if (count < G.VertexNodeCount)
{
Console.Write("图中有环,排序失败");
}
else
{
Console.Write("拓扑排序结果如下 : \n" + SB);
}
}