public static void SetUpUnDirectedGraph(KarthicGraph <int> graph)
{
GraphNode <int> node1 = new GraphNode <int>(0);
GraphNode <int> node2 = new GraphNode <int>(1);
GraphNode <int> node3 = new GraphNode <int>(2);
GraphNode <int> node4 = new GraphNode <int>(3);
GraphNode <int> node5 = new GraphNode <int>(4);
GraphNode <int> node6 = new GraphNode <int>(5);
GraphNode <int> node7 = new GraphNode <int>(6);
//Add vertices
graph.AddNode(node1);
graph.AddNode(node2);
graph.AddNode(node3);
graph.AddNode(node4);
graph.AddNode(node5);
graph.AddNode(node6);
graph.AddNode(node7);
//Add edges
graph.AddUndirectedEdge(node1, node2);
graph.AddUndirectedEdge(node1, node3);
graph.AddUndirectedEdge(node1, node4);
graph.AddUndirectedEdge(node2, node5);
graph.AddUndirectedEdge(node5, node7);
graph.AddUndirectedEdge(node4, node6);
//graph.AddDirectedEdge(new GraphNode<int>(4), new GraphNode<int>(6));
}
private void button6_Click(object sender, EventArgs e)
{
//Implemenataion. Deep copy a graph
KarthicGraph <int> graph = new KarthicGraph <int>();
TreeHelper.SetUpUnDirectedGraph(graph);
KarthicGraph <int> deepcopiedgraph = DeepCopyGraph(graph);
}
private void button9_Click(object sender, EventArgs e)
{
KarthicGraph <int> graph = new KarthicGraph <int>();
TreeHelper.SetUpGraph(graph);
StringBuilder output = new StringBuilder();
graph.BreadthFirstSearch(graph.Root, output);
this.textBox9.Text = output.ToString();
}
private void button3_Click(object sender, EventArgs e)
{
KarthicGraph <int> graph = new KarthicGraph <int>();
TreeHelper.SetUpUnDirectedGraph(graph);
GraphNode <int> startnode = graph.FindNodeByValue(Convert.ToInt16(this.textBox4.Text));
GraphNode <int> endnode = graph.FindNodeByValue(Convert.ToInt16(this.textBox1.Text));
bool result = graph.IsRouteExists(startnode, endnode);
this.textBox2.Text = (result == true) ? "Route Exists" : "No route exists";
}
public KarthicGraph <int> DeepCopyGraph(KarthicGraph <int> graph)
{
Hashtable ht = new Hashtable();
GraphNode <int> root = graph.Root;
KarthicGraph <int> copygraph = new KarthicGraph <int>();
Queue <GraphNode <int> > myqueue = new Queue <GraphNode <int> >();
myqueue.Enqueue(root);
//hashtable will have original node as key and copied node as data
GraphNode <int> copynode = new GraphNode <int>(root.Data);
ht.Add(root, copynode);
copygraph.Root = copynode;
while (myqueue.Count != 0)
{
GraphNode <int> parent = myqueue.Dequeue();
foreach (GraphNode <int> child in parent.Neighbors)
{
//make sure you check for exists..
//if exists means already added/visited etc..
//this will catch the undirected structre a -> b and b ->a
if (!ht.ContainsKey(child))
{
GraphNode <int> childcopy = new GraphNode <int>(child.Data);
ht.Add(child, childcopy);
myqueue.Enqueue(child);
}
//get the copy of the parent and add the created childcopy to its neighbor
((GraphNode <int>)ht[parent]).Neighbors.Add((GraphNode <int>)ht[child]);
//else
//{
// //here it mean the child is alredy visited and added to ht by its parent
// //unidirection ..we are adding only the copy
// ((GraphNode<int>)ht[child]).Neighbors.Add((GraphNode<int>)ht[parent]);
// //we don't add to queue to prevent loop
//}
}
}
return(copygraph);
}
public bool BuildGraph(int startx, int starty, int size, char endgoal, char[,] maze, GraphNode <char> parent, KarthicGraph <char> graph)
{
//Base case
//check for outside bounds
if (startx < 0 || startx >= size || starty < 0 || starty >= size)
{
return(false);
}
//check for obstacle
if (maze[startx, starty] == '#')
{
return(false);
}
//check if already visited..to prevent loop
if (maze[startx, starty] == '+')
{
return(false);
}
//when the code comes means the path is free and goal not found so traverse in all direction
GraphNode <char> child = new GraphNode <char>(maze[startx, starty]);
child.XAxis = startx;
child.YAxis = starty;
// child.Marked = true;
graph.AddNode(child);
graph.AddDirectedEdge(parent, child);
//parent.Neighbors.Add(child);
//check for goal
if (maze[startx, starty] == endgoal)
{
return(true);
}
//Mark the current point as visited
maze[startx, starty] = '+';
//search in north of the point
if (BuildGraph(startx - 1, starty, size, endgoal, maze, child, graph))
{
return(true);
}
//search in the east of the point
if (BuildGraph(startx, starty + 1, size, endgoal, maze, child, graph))
{
return(true);
}
//search in the south of the point
if (BuildGraph(startx + 1, starty, size, endgoal, maze, child, graph))
{
return(true);
}
//search in the west of the point
if (BuildGraph(startx, starty - 1, size, endgoal, maze, child, graph))
{
return(true);
}
//goal not found ..unmark the point
maze[startx, starty] = '.';
// child.Marked = false;
return(false);
}
