/// <summary>
/// Process a node, finding new paths
/// </summary>
/// <param name="node">The current node</param>
/// <param name="path">The path travelled so far</param>
public void ProcessNode(FieldCoord node, List <FieldCoord> path)
{
List <FieldCoord> border = GetBorder(node);
foreach (FieldCoord newnode in border)
{
bool present = false;
foreach (FieldCoord fc in path)
{
if (fc.Row == newnode.Row && fc.Col == newnode.Col)
{
present = true;
break;
}
}
if (!present)
{
List <FieldCoord> newpath = new List <FieldCoord>(path);
newpath.Add(newnode);
if (mGrid.GetCell(newnode.Row, newnode.Col) == FieldElement.Finish)
{
mSolutions.Add(newpath);
}
else
{
ProcessNode(newnode, newpath);
}
}
}
}
/// <summary>
/// Get the closest elements to this grid cell
/// </summary>
/// <param name="node">The coodinates related to the current grid cell</param>
/// <returns>The elements in the border</returns>
private List <FieldCoord> GetBorder(FieldCoord node)
{
List <FieldCoord> border = new List <FieldCoord>();
// North
if (node.Row - 1 >= 0)
{
FieldElement elem = mGrid.GetCell(node.Row - 1, node.Col);
if (elem == FieldElement.Empty || elem == FieldElement.Finish)
{
border.Add(new FieldCoord(node.Row - 1, node.Col));
}
}
// South
if (node.Row + 1 < mGrid.Rows)
{
FieldElement elem = mGrid.GetCell(node.Row + 1, node.Col);
if (elem == FieldElement.Empty || elem == FieldElement.Finish)
{
border.Add(new FieldCoord(node.Row + 1, node.Col));
}
}
// West
if (node.Col - 1 >= 0)
{
FieldElement elem = mGrid.GetCell(node.Row, node.Col - 1);
if (elem == FieldElement.Empty || elem == FieldElement.Finish)
{
border.Add(new FieldCoord(node.Row, node.Col - 1));
}
}
// East
if (node.Col + 1 < mGrid.Cols)
{
FieldElement elem = mGrid.GetCell(node.Row, node.Col + 1);
if (elem == FieldElement.Empty || elem == FieldElement.Finish)
{
border.Add(new FieldCoord(node.Row, node.Col + 1));
}
}
return(border);
}
/// <summary>
/// Found the solutions of the maze with depth first algorithm
/// </summary>
public void Solve()
{
mStart = FindFieldElement(FieldElement.Start);
mFinish = FindFieldElement(FieldElement.Finish);
if (mStart == null || mFinish == null)
{
return;
}
List <FieldCoord> path = new List <FieldCoord>();
path.Add(mStart);
ProcessNode(mStart, path);
}
