// Graph/Tree Traversal (Group A) is implemented here.
private void ButtonNext_Click(object sender, EventArgs e)
{
if (buttonNext.Text == "Close")
{
this.Close();
}
else
{
labelInformation.Visible = true;
// Step 1 operation
if (currentStep == 1)
{
// Highlight current step
label1.ForeColor = Color.Red;
labelStep1.ForeColor = Color.Red;
label2.ForeColor = SystemColors.ControlText;
labelStep2.ForeColor = SystemColors.ControlText;
label3.ForeColor = SystemColors.ControlText;
labelStep3.ForeColor = SystemColors.ControlText;
// Initialise Prim's algorithm
for (int i = 0; i < mapMatrix.GetSize(); i++)
{
if (mapMatrix.IsVertexExisting(i))
{
remainingVertices.Add(i);
}
}
labelInformation.Text = "Please pick a vertex of your choice:\nPlease click on the vertex of the graph.";
buttonNext.Enabled = false;
}
// Step 2 operation
else if (currentStep == 2)
{
// Highlight current step
label1.ForeColor = SystemColors.ControlText;
labelStep1.ForeColor = SystemColors.ControlText;
label2.ForeColor = Color.Red;
labelStep2.ForeColor = Color.Red;
label3.ForeColor = SystemColors.ControlText;
labelStep3.ForeColor = SystemColors.ControlText;
// Find minimum value of edge weight and candidate edges
double min = Double.MaxValue;
List <int[]> candidateEdges = new List <int[]>();
foreach (int i in visitedVertices)
{
foreach (int j in remainingVertices)
{
if (mapMatrix.ContainsEdge(i, j) && mapMatrix.GetEdge(i, j) < min) // Find minimum value of edge weight
{
min = mapMatrix.GetEdge(i, j);
}
}
}
foreach (int i in visitedVertices)
{
foreach (int j in remainingVertices)
{
if (mapMatrix.ContainsEdge(i, j) && mapMatrix.GetEdge(i, j) == min) // Find candidate edges
{
candidateEdges.Add(new int[2] {
i, j
});
}
}
}
// More than two candidate edges - User operation required
if (candidateEdges.Count >= 2)
{
// Show explanation
labelInformation.Text = "Edges ";
foreach (int[] edge in candidateEdges)
{
labelInformation.Text += Convert.ToChar(edge[0] + 'A').ToString() + Convert.ToChar(edge[1] + 'A').ToString() + ", ";
}
labelInformation.Text = labelInformation.Text.TrimEnd(", ".ToCharArray());
labelInformation.Text += " have the same weight (" + min.ToString() + "). Please pick one of your choice:\n"
+ "Please click on the vertex or the weight.";
// Highlight candidate edges
for (int i = 0; i < candidateEdges.Count; i++)
{
int v1 = Math.Min(candidateEdges[i][0], candidateEdges[i][1]);
int v2 = Math.Max(candidateEdges[i][0], candidateEdges[i][1]);
string labelName = "label" + Convert.ToChar(v1 + 'A').ToString() + Convert.ToChar(v2 + 'A').ToString();
foreach (Label label in exampleGraph.labelWeights)
{
if (label.Name == labelName)
{
label.ForeColor = Color.Red;
break;
}
}
foreach (Vertex vertex in vertices)
{
if (vertex.GetNumberIndex() == candidateEdges[i][1])
{
vertex.labelName.ForeColor = Color.Red;
break;
}
}
}
currentStep = 2;
buttonNext.Enabled = false;
}
// Only one candidate edge avaliable - No user operation needed
else
{
// Show explanation
int[] newEdge = new int[2] {
candidateEdges[0][0], candidateEdges[0][1]
};
labelInformation.Text = "Edge " + Convert.ToChar(candidateEdges[0][0] + 'A').ToString() + Convert.ToChar(candidateEdges[0][1] + 'A').ToString()
+ " has the minimum weight joining a vertex already included to a vertex not already included (" + min.ToString() + "),"
+ " therefore it has been added to the Minimum Spanning Tree.";
// Update Prim's algorithm
foreach (Vertex vertex in vertices)
{
if (vertex.GetNumberIndex() == newEdge[1])
{
weightMST += min;
labelTotalWeight.Text += min.ToString() + " + ";
visitedVertices.Add(newEdge[1]);
remainingVertices.Remove(newEdge[1]);
EdgeFocusOn(newEdge[0], newEdge[1]);
exampleGraph.LabelFocusOn(newEdge[0], newEdge[1]);
currentStep = 3;
break;
}
}
}
}
// Step 3 operation
else // if (currentStep == 3)
{
// Highlight current steps
label1.ForeColor = SystemColors.ControlText;
labelStep1.ForeColor = SystemColors.ControlText;
label2.ForeColor = SystemColors.ControlText;
labelStep2.ForeColor = SystemColors.ControlText;
label3.ForeColor = Color.Red;
labelStep3.ForeColor = Color.Red;
// Check if Prim's algorithm has finished
if (remainingVertices.Any())
{
labelInformation.Text = "We have not yet formed a Minimum Spanning Tree, so go back to STEP 2.";
currentStep = 2;
}
else
{
labelInformation.Text = "Now we have picked " + (mapMatrix.Count() - 1).ToString() + " edges and has formed a Minimum Spanning Tree.\nTherefore Prim's algorithm has finished.";
labelTotalWeight.Text = labelTotalWeight.Text.TrimEnd(" + ".ToCharArray());
labelTotalWeight.Text += " = " + weightMST.ToString();
labelTotalWeight.Visible = true;
buttonNext.Text = "Close";
}
}
}
}
// Graph/Tree Traversal (Group A) is implemented here.
private void ButtonNext_Click(object sender, EventArgs e)
{
if (buttonNext.Text == "Close")
{
this.Close();
}
else
{
// Step 1 operation
if (currentStep == 1)
{
// Highlight current step
label1.ForeColor = Color.Red;
labelStep1.ForeColor = Color.Red;
label2.ForeColor = SystemColors.ControlText;
labelStep2.ForeColor = SystemColors.ControlText;
label3.ForeColor = SystemColors.ControlText;
labelStep3.ForeColor = SystemColors.ControlText;
// Show the headers of the list of all edges
labelList.Visible = true;
labelEdgeLeft.Visible = true;
labelWeightLeft.Visible = true;
labelEdgeRight.Visible = true;
labelWeightRight.Visible = true;
// Initialise and sort the list of all edges
int edgeCount = 0;
for (int v1 = 0; v1 < mapMatrix.GetSize() - 1; v1++)
{
for (int v2 = v1 + 1; v2 < mapMatrix.GetSize(); v2++)
{
if (mapMatrix.ContainsEdge(v1, v2))
{
edgeCount++;
edgeList.Add(new Edge
{
vStart = v1,
vFinish = v2,
weight = mapMatrix.GetEdge(v1, v2)
});
}
}
}
edgeCount /= 2;
QuickSort(edgeList, 0, edgeList.Count - 1);
// Show the list of all edges
Point[] originalLocations = new Point[2];
originalLocations[0] = new Point(24, 332);
originalLocations[1] = new Point(originalLocations[0].X + 228, originalLocations[0].Y);
for (int i = 0; i < edgeList.Count; i++)
{
Point location = new Point(originalLocations[i / edgeCount].X, originalLocations[i / edgeCount].Y + 44 * (i % edgeCount));
labelEdges.Add(new Label()
{
AutoSize = true,
Font = new Font("Microsoft YaHei", 12F, FontStyle.Bold, GraphicsUnit.Point, ((byte)(134))),
Location = location,
MinimumSize = new Size(100, 44),
Name = "labelEdge" + i.ToString(),
Size = new Size(100, 44),
Text = Convert.ToChar(edgeList[i].vStart + 'A').ToString() + Convert.ToChar(edgeList[i].vFinish + 'A').ToString(),
TextAlign = ContentAlignment.TopCenter
});
labelEdges[i].Click += new EventHandler(LabelEdge_Click);
labelWeights.Add(new Label()
{
AutoSize = true,
Font = new Font("Microsoft YaHei", 12F, FontStyle.Bold, GraphicsUnit.Point, ((byte)(134))),
Location = new Point(location.X + 100, location.Y),
MinimumSize = new Size(100, 44),
Name = "labelWeight" + i.ToString(),
Size = new Size(100, 44),
Text = edgeList[i].weight.ToString(),
TextAlign = ContentAlignment.TopCenter
});
labelWeights[i].Click += new EventHandler(LabelEdge_Click);
labelEdgeUsed.Add(new Label()
{
AutoSize = true,
Font = new Font("Microsoft YaHei", 12F, FontStyle.Bold, GraphicsUnit.Point, ((byte)(134))),
Location = new Point(location.X + 200, location.Y),
MinimumSize = new Size(0, 22),
Name = "labelEdgeUsed" + i.ToString(),
Size = new Size(22, 22),
Text = "×",
TextAlign = ContentAlignment.TopCenter,
Visible = false
});
this.Controls.Add(labelEdges[i]);
this.Controls.Add(labelWeights[i]);
this.Controls.Add(labelEdgeUsed[i]);
}
currentEdgeIndex = 0;
currentWeight = edgeList[0].weight;
currentStep = 2;
}
// Step 2 operations
else if (currentStep == 2)
{
// Highlight current step
label1.ForeColor = SystemColors.ControlText;
labelStep1.ForeColor = SystemColors.ControlText;
label2.ForeColor = Color.Red;
labelStep2.ForeColor = Color.Red;
label3.ForeColor = SystemColors.ControlText;
labelStep3.ForeColor = SystemColors.ControlText;
foreach (Label label in labelEdges)
{
label.ForeColor = SystemColors.ControlText;
}
foreach (Label label in labelWeights)
{
label.ForeColor = SystemColors.ControlText;
}
labelEdges[currentEdgeIndex].ForeColor = Color.Red;
labelWeights[currentEdgeIndex].ForeColor = Color.Red;
// Initialise text explanation label
labelInformation.Text = "";
labelInformation.Visible = true;
// Perform Kruskal's algorithm
if (Find(edgeList[currentEdgeIndex].vStart).GetLeader() == Find(edgeList[currentEdgeIndex].vFinish).GetLeader()) // Reject edges forming a cycle
{
labelInformation.Text = "Adding edge " + labelEdges[currentEdgeIndex].Text + " will form a cycle, therefore edge " + labelEdges[currentEdgeIndex].Text + " should not be chosen.";
labelEdgeUsed[currentEdgeIndex].Text = "×";
labelEdgeUsed[currentEdgeIndex].ForeColor = Color.Red;
labelEdgeUsed[currentEdgeIndex].Visible = true;
labelEdges[currentEdgeIndex].Font = new Font("Microsoft YaHei", 12F, ((System.Drawing.FontStyle)((System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Strikeout))), System.Drawing.GraphicsUnit.Point, ((byte)(134)));
labelWeights[currentEdgeIndex].Font = new Font("Microsoft YaHei", 12F, ((System.Drawing.FontStyle)((System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Strikeout))), System.Drawing.GraphicsUnit.Point, ((byte)(134)));
do
{
currentEdgeIndex++;
} while (labelEdgeUsed[currentEdgeIndex].Visible);
currentWeight = edgeList[currentEdgeIndex].weight;
currentStep = 2;
}
else
{
int i = currentEdgeIndex + 1;
List <Edge> tempEdgeList = new List <Edge>
{
edgeList[currentEdgeIndex]
};
while (edgeList[i].weight == currentWeight && !labelEdgeUsed[i].Visible)
{
if (Find(edgeList[i].vStart).GetLeader() != Find(edgeList[i].vFinish).GetLeader()) // Highlight feasible candidate edges
{
labelEdges[i].ForeColor = Color.Red;
labelWeights[i].ForeColor = Color.Red;
tempEdgeList.Add(edgeList[i]);
}
else // Reject edges forming a cycle
{
labelInformation.Text += "Adding edge " + labelEdges[i].Text + " will form a cycle, therefore edge " + labelEdges[i].Text + " should not be chosen.\n";
labelEdgeUsed[i].Text = "×";
labelEdgeUsed[i].ForeColor = Color.Red;
labelEdgeUsed[i].Visible = true;
labelEdges[i].Font = new Font("Microsoft YaHei", 12F, ((System.Drawing.FontStyle)((System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Strikeout))), System.Drawing.GraphicsUnit.Point, ((byte)(134)));
labelWeights[i].Font = new Font("Microsoft YaHei", 12F, ((System.Drawing.FontStyle)((System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Strikeout))), System.Drawing.GraphicsUnit.Point, ((byte)(134)));
}
i++;
}
if (tempEdgeList.Count >= 2) // More than two candidate edges - user operation required
{
labelInformation.Text += "Edges ";
foreach (Edge edge in tempEdgeList)
{
labelInformation.Text += Convert.ToChar(edge.vStart + 'A').ToString() + Convert.ToChar(edge.vFinish + 'A').ToString() + ", ";
}
labelInformation.Text = labelInformation.Text.TrimEnd(", ".ToCharArray());
labelInformation.Text += " have the same weight. Please pick one of your choice.\n"
+ "Please click on the edge in the list (NOT on the graph).";
currentStep = 2;
buttonNext.Enabled = false;
}
else // One candidate edge only
{
labelInformation.Text += "Edge " + labelEdges[currentEdgeIndex].Text + " has been added to the Minimum Spanning Tree.";
labelEdgeUsed[currentEdgeIndex].Text = "√";
labelEdgeUsed[currentEdgeIndex].ForeColor = Color.Green;
labelEdgeUsed[currentEdgeIndex].Visible = true;
EdgeFocusOn(edgeList[currentEdgeIndex].vStart, edgeList[currentEdgeIndex].vFinish);
exampleGraph.LabelFocusOn(edgeList[currentEdgeIndex].vStart, edgeList[currentEdgeIndex].vFinish);
treeEdgeCount++;
weightMST += currentWeight;
Union(Find(edgeList[currentEdgeIndex].vStart).GetLeader(), Find(edgeList[currentEdgeIndex].vFinish).GetLeader());
currentEdgeIndex = i;
while (labelEdgeUsed[currentEdgeIndex].Visible)
{
currentEdgeIndex++;
}
currentWeight = edgeList[currentEdgeIndex].weight;
currentStep = 3;
}
}
}
// Step 3 operation
else // if (currentStep == 3)
{
// Highlight current step
label1.ForeColor = SystemColors.ControlText;
labelStep1.ForeColor = SystemColors.ControlText;
label2.ForeColor = SystemColors.ControlText;
labelStep2.ForeColor = SystemColors.ControlText;
label3.ForeColor = Color.Red;
labelStep3.ForeColor = Color.Red;
foreach (Label label in labelEdges)
{
label.ForeColor = SystemColors.ControlText;
}
foreach (Label label in labelWeights)
{
label.ForeColor = SystemColors.ControlText;
}
// Initialise text explanation label
labelInformation.Text = "";
labelInformation.Visible = true;
// Check if the algorithm is finished
if (treeEdgeCount < mapMatrix.Count() - 1)
{
labelInformation.Text = "We have not yet formed a Minimum Spanning Tree, so go back to STEP 2.";
currentStep = 2;
}
else
{
labelInformation.Text = "Now we have picked " + (mapMatrix.Count() - 1).ToString() + " edges and has formed a Minimum Spanning Tree.\nTherefore Kruskal's algorithm has finished.";
for (int i = 0; i < edgeList.Count; i++)
{
if (labelEdgeUsed[i].Text == "√")
{
labelTotalWeight.Text += labelWeights[i].Text + " + ";
}
}
labelTotalWeight.Text = labelTotalWeight.Text.TrimEnd(" + ".ToCharArray());
labelTotalWeight.Text += " = " + weightMST.ToString();
labelTotalWeight.Visible = true;
buttonNext.Text = "Close";
}
}
}
}
public FormPrimOnMatrix(int accountID, string username, string accountName, string accountType, int example)
{
InitializeComponent();
// Show account name on the account menu.
this.accountMenu.accountID = accountID;
this.accountMenu.username = username;
this.accountMenu.labelAccountName.Text = accountName;
this.accountMenu.accountType = accountType;
this.example = example;
// Select the correct example graph to perform the demonstration.
if (example == 1)
{
exampleGraph = new MinimumSpanningTreeExample1(this.panelGraph);
}
else
{
exampleGraph = new MinimumSpanningTreeExample2(this.panelGraph);
}
// Initialise the example graph.
vertices = exampleGraph.GetVertices();
mapMatrix = exampleGraph.GetMatrix();
// Initialise the table for the example graph.
for (int i = 0; i <= mapMatrix.Count(); i++)
{
DataGridViewColumn newColumn = new DataGridViewColumn
{
CellTemplate = new DataGridViewTextBoxCell(),
SortMode = System.Windows.Forms.DataGridViewColumnSortMode.NotSortable,
Width = 60
};
if (i == 0)
{
newColumn.Width = 41;
}
dataGridViewGraph.Columns.Add(newColumn);
}
int count = 1;
for (int i = 0; i < mapMatrix.GetSize(); i++)
{
if (mapMatrix.IsVertexExisting(i))
{
dataGridViewGraph.Columns[count].HeaderText = Convert.ToChar('A' + i).ToString();
dataGridViewGraph.Columns[count].Name = "Column" + dataGridViewGraph.Columns[count].HeaderText;
count++;
}
}
count = 0;
this.dataGridViewGraph.RowCount = mapMatrix.Count();
for (int i = 0; i < mapMatrix.GetSize(); i++)
{
if (mapMatrix.IsVertexExisting(i))
{
this.dataGridViewGraph[0, count++].Value = (Convert.ToChar('A' + i)).ToString();
}
}
for (int col = 1; col <= mapMatrix.Count(); col++)
{
for (int row = 0; row < mapMatrix.Count(); row++)
{
int vStartIndex = mapMatrix.GetVertexIndex(dataGridViewGraph.Columns[col].HeaderText);
int vFinishIndex = mapMatrix.GetVertexIndex(this.dataGridViewGraph[0, row].Value.ToString());
if (mapMatrix.ContainsEdge(vStartIndex, vFinishIndex))
{
this.dataGridViewGraph[col, row].Value = mapMatrix.GetEdge(vStartIndex, vFinishIndex);
}
else
{
this.dataGridViewGraph[col, row].Value = "-";
}
}
}
}