public void IsUnDirectedCyclic()
{
UnDirectedGraph g = new UnDirectedGraph(5);
g.AddEdge(1, 0);
g.AddEdge(0, 2);
g.AddEdge(2, 0);
g.AddEdge(0, 3);
g.AddEdge(3, 4);
Console.WriteLine(IsUnDirectedCyclic(g));
}
private bool IsUnDirectedCyclic(UnDirectedGraph graph)
{
for (int idx = 0; idx < graph.Vertices; idx++)
{
if (!graph.Visited[idx])
{
if (IsUnDirectedCyclicUtil(graph, idx, -1))
{
return(true);
}
}
}
return(false);
}
private bool IsUnDirectedCyclicUtil(UnDirectedGraph graph, int vertex, int parent)
{
graph.Visited[vertex] = true;
if (graph.AdjList.ContainsKey(vertex))
{
foreach (int idx in graph.AdjList[vertex])
{
if (!graph.Visited[idx])
{
if (IsUnDirectedCyclicUtil(graph, idx, vertex))
{
return(true);
}
}
else if (idx != parent)
{
return(true);
}
}
}
return(false);
}