private void DFS(IDirectedGraph graph, int vertex)
{
onStack[vertex] = true;
isConnected[vertex] = true;
foreach (int v in graph.Adjacent(vertex))
{
if (HasCycle())
{
return;
}
if (!isConnected[v])
{
edgeTo[v] = vertex;
DFS(graph, v);
}
// 如果当前相邻顶点被标记过，并且在递归调用栈上，说明路径又回到了之前的顶点，也就是出现环路
else if (onStack[v])
{
cycle = new Stack <int>();
// 把路径上的所有顶点记录下来
for (int i = vertex; i != v; i = edgeTo[i])
{
cycle.Push(i);
}
cycle.Push(v);
cycle.Push(vertex);
}
}
onStack[vertex] = false;
}
private void DFS(IDirectedGraph graph, int vertex)
{
isConnected[vertex] = true;
id[vertex] = count;
foreach (var v in graph.Adjacent(vertex))
{
if (!isConnected[v])
{
DFS(graph, v);
}
}
}
private void DFS(IDirectedGraph graph, int vertex)
{
pre.Enqueue(vertex);
isConnected[vertex] = true;
foreach (int v in graph.Adjacent(vertex))
{
if (!isConnected[v])
{
DFS(graph, v);
}
}
post.Enqueue(vertex);
reversePost.Push(vertex);
}