public void BFS_Search(GraphClass graph, int root, string val)//this is similar to BFS_Traverse method
{
//explore root
if (graph.vertices[root].Value == val)//if the value is equal to the root vertex, return
{
MessageBox.Show("Found vertex: " + val);
return;
}
for (int i = 0; i < graph.Size; i++)
{
if (graph.matrix[root, i] == 1 && graph.vertices[i].isVisited == false) //if the node is not visited and the value is 1
{
Enque(i); //put the vertex in the queue. put it in the last
graph.vertices[i].isVisited = true; //set that vertex to true
}
}
Qhead = Qhead + 1; //increment the pointer to be traversed
if (Qtail <= Qhead) //this is the termination code. When head pointer is already pointing to tail.
//meaning all nodes are visited and cannot find the value
{
MessageBox.Show("Cannot find vertex: " + val);
return;
}
root = Deque(); //get the first value of the Queue ans set to new root
BFS_Search(graph, root, val); //traverse again the root
}
public void BFS_Search_Display(GraphClass graph, string val)
{
Queue_ = new int[graph.Size]; //set the size of the Q to the size of the graph
Enque(0); //start from 0 index
graph.vertices[0].isVisited = true; //set that vertex to visited
BFS_Search(graph, 0, val); //traverse the vertex 0
}
public void BFS_Display(GraphClass graph)
{
Queue_ = new int[graph.Size]; //set the size of the Q to the size of the graph
Enque(0); //start from 0 index
graph.vertices[0].isVisited = true; //set that vertex to visited
BFS_Traverse(graph, 0); //traverse the vertex 0
PrintQueue(graph); // print all the values after traversal
}
public void PrintQueue(GraphClass graph)//traverse the values in the queue
{
string str = "";
foreach (int element in Queue_)
{
str = str + graph.vertices[element].Value + ",";
}
MessageBox.Show(str, "DFS Traversal");
}
public void printVertices(GraphClass graph)//method to print vertices of a graph
{
string elements = "";
foreach (Vertex element in graph.vertices)
{
elements = elements + element.Value + " ";
}
MessageBox.Show(elements);
}
//-------------------------------------------------------------------------------------
//-------------------------DEPTH FIRST SEARCH----------------------------------------
public void DFS_Traverse(GraphClass graph, int root, int neighbor) //DEPTH FIRST SEARCH TRAVERSAL
{
if (root < graph.Size) //ensure that the vertex is checking is not greater than the size of a grpah
{
if (graph.vertices[root].isVisited == true) //if the vertex is visited, go to next vertex
{
return;
}
graph.vertices[root].isVisited = true; //else, visit the vertex and set the IsVisited to True
print = print + graph.vertices[root].Value + ","; //put the vertex value in the variable for printing later
while (graph.matrix[root, neighbor] == 0) //loop though tha columns (neighbor/adjacent) of root while its 0. If its 0, exit from while loop
{
neighbor++; //increment the column
//when all columns are 0, meaning no adjacent vertex, exit the loop
if (root >= graph.Size || neighbor >= graph.Size)//if that columns is exceeding the graph size
{
break;
}
}
//when the matrix [root, neighbor] value is 1, then set that column to new root
DFS_Traverse(graph, neighbor, 0);//traverse that new root again
//If it is the end of the traversal, then backtrack
for (int x = neighbor + 1; x < graph.Size; x++) //loop the next column
{
if (graph.matrix[root, x] == 1) //if the next column is 1, then traverse again
{
DFS_Traverse(graph, x, 0);
break;
}
else//if 0, then loop until 1 is encountered
{
continue;
}
}
}
}
public void BFS_Traverse(GraphClass graph, int root)
{
//explore root
for (int i = 0; i < graph.Size; i++)
{
if (graph.matrix[root, i] == 1 && graph.vertices[i].isVisited == false) //if the node is not visited and the value is 1
{
Enque(i); //put the vertex in the queue. put it in the last
graph.vertices[i].isVisited = true; //set that vertex to true
}
}
Qhead = Qhead + 1; //increment the pointer to be traversed
if (Qtail <= Qhead) //this is the termination code. When head pointer is already pointing to tail. meaning all nodes are visited
{
return;
}
root = Deque(); //get the first value of the Queue ans set to new root
BFS_Traverse(graph, root); //traverse that root
}
public void DisplayMatrix(GraphClass graph)//display the matrix
{
if (graph == graph1)
{
CreateMatrix1();
}
if (graph == graph2)
{
CreateMatrix2();
}
string val = "";
for (int i = 0; i < graph.Size; i++) // loop though the matrix row
{
for (int j = 0; j < graph.Size; j++) // loop though the matrix column
{
val = val + graph.matrix[i, j].ToString() + " ";
}
val = val + "\n";
}
MessageBox.Show(val, "Matrix");
}
//method on adding edge
public void addEdge(GraphClass graph, string From, string To)
{
//no need for me to loop through the matrix since I have hash table already
graph.matrix[hashFIndex(graph.vertices, From), hashFIndex(graph.vertices, To)] = 1;
}
public void DFS_Search_Display(GraphClass graph, string val)
{
Stack = new int[graph.Size]; //create the stack
Stacktail = 0; //set the tail to 0 where can insert the vertex
DFS_Search(graph, 0, 0, val); //start from 0 index
}
public int Stacktail; //pointer for stack
public void DFS_Search(GraphClass graph, int root, int neighbor, string val)
{
if ((root >= graph.Size))// if the root is greater than the size, return
{
MessageBox.Show("Cannot find vertex: " + val);
return;
}
if (graph.vertices[root].Value == val)//if the value is equal to the root vertex, return
{
MessageBox.Show("Found vertex: " + val);
return;
}
else
{
//push on stack
if (graph.vertices[root].isVisited == false)
{
Push(root); //push the root vertex to the stack
graph.vertices[root].isVisited = true; //make that vertex visited
//get the adjacent value
while (graph.matrix[root, neighbor] == 0)
{
neighbor++;
if (root >= graph.Size || neighbor >= graph.Size)//if cannot find
{
break;
}
}
//when the matrix [root, neighbor] value is 1, then set that column to new root
root = neighbor;
DFS_Search(graph, root, 0, val); //traverse that new root again
}
else if (graph.vertices[root].isVisited == true) //if visted already, back track
{
neighbor = root + 1; //mov to the next adjacent vertex
root = Pop(); // pop the top value in the stack and make it as a root
//back track. Traverse that root
while (graph.matrix[root, neighbor] == 0)
{
neighbor++;
if (root >= graph.Size || neighbor >= graph.Size)//if cannot find
{
break;
}
}
if (neighbor >= graph.Size) //no more adjacent vertex
{
neighbor = root; //save the previous adjacent
DFS_Search(graph, root, neighbor, val); // traverse again
}
else//make that adjacent vertex as the new root to traverse
{
root = neighbor;
DFS_Search(graph, root, 0, val);//traverse again
}
}
}
}
public void DFS_Display(GraphClass graph) //Display the DFS Traversal of a graph
{
DFS_Traverse(graph, 0, 0); // starts from vertex 0
MessageBox.Show(print, "DFS Traversal");
}