public void Solve(IMazeGrid maze, Action <IEnumerable <IMazeCell> > solvedResultCallback)
{
Graph <IMazeCell> graph = maze.GenerateGraph();
// stack of graph nodes
Stack <GraphNode <IMazeCell> > stack = new Stack <GraphNode <IMazeCell> >();
// Routes Collection
LinkedList <GraphNode <IMazeCell> > visited = new LinkedList <GraphNode <IMazeCell> >();
GraphNode <IMazeCell> startNode = (GraphNode <IMazeCell>)graph.Nodes.FindByValue(maze.Start);
stack.Push(startNode);
GraphNode <IMazeCell> currentNode = null;
while (stack.Count > 0)
{
currentNode = stack.Pop();
_logger.LogTrace($"Poped Node: {currentNode.Value.ToString()}");
if (visited.Contains(currentNode))
{
continue;
}
visited.AddFirst(currentNode);
if (maze.Finish.Equals(currentNode.Value))
{
_logger.LogTrace($"Found Finish Node: {currentNode.Value.ToString()}");
solvedResultCallback(TraceSolvedPath(visited));
}
// Examine neighbor nodes
foreach (GraphNode <IMazeCell> neighbor in currentNode.Neighbors)
{
if (!visited.Contains(neighbor))
{
stack.Push(neighbor);
_logger.LogTrace($"Push Node: {neighbor.Value.ToString()}");
}
else
{
_logger.LogTrace($"Node: {neighbor.Value.ToString()} is visited");
}
}
}
}
public void Solve(IMazeGrid maze, Action <IEnumerable <IMazeCell> > solvedResultCallback)
{
Graph <IMazeCell> graph = maze.GenerateGraph();
// stack of graph nodes
LinkedList <GraphNode <IMazeCell> > visited = new LinkedList <GraphNode <IMazeCell> >(); //collecting all routes
GraphNode <IMazeCell> startNode = (GraphNode <IMazeCell>)graph.Nodes.FindByValue(maze.Start);
GraphNode <IMazeCell> endNode = (GraphNode <IMazeCell>)graph.Nodes.FindByValue(maze.Finish);
visited.AddFirst(startNode);
// make the first call
BreadthFirst(startNode, endNode, visited, solvedResultCallback);
}
public void Solve(IMazeGrid maze, Action <IEnumerable <IMazeCell> > solvedResultCallback)
{
// the maze graph
Graph <IMazeCell> graph = maze.GenerateGraph();
// List of Accepted solutions used to reset the visited nodes
List <List <GraphNode <IMazeCell> > > solutions = new List <List <GraphNode <IMazeCell> > >();
// Que of graph nodes
Queue <GraphNode <IMazeCell> > queue = new Queue <GraphNode <IMazeCell> >();
// Directory of Predecessor
Dictionary <GraphNode <IMazeCell>, GraphNode <IMazeCell> > predecessors = new Dictionary <GraphNode <IMazeCell>, GraphNode <IMazeCell> >();
// List visited nodes
List <GraphNode <IMazeCell> > visited = new List <GraphNode <IMazeCell> >();
GraphNode <IMazeCell> currentNode = null;
GraphNode <IMazeCell> startNode = (GraphNode <IMazeCell>)graph.Nodes.FindByValue(maze.Start);
queue.Enqueue(startNode);
while (queue.Count > 0)
{
currentNode = queue.Dequeue();
_logger.LogTrace($"Dequeue Node({currentNode.Value.ToString()})");
if (visited.Contains(currentNode))
{
continue;
}
visited.Add(currentNode);
if (maze.Finish.Equals(currentNode.Value))
{
_logger.LogTrace($"Finish Node({currentNode.Value.ToString()})");
IEnumerable <GraphNode <IMazeCell> > solvedPath = TraceSolvedPath(currentNode, predecessors);
// callback Action and returns path.
List <IMazeCell> cbPath = new List <IMazeCell>();
foreach (var node in solvedPath)
{
cbPath.Add(node.Value);
}
solvedResultCallback(cbPath);
break;
}
foreach (GraphNode <IMazeCell> neighbor in currentNode.Neighbors)
{
if (!visited.Contains(neighbor) && !queue.Contains(neighbor))
{
// enquew
queue.Enqueue(neighbor);
// keep track of Predecessor
predecessors[neighbor] = currentNode;
_logger.LogTrace($"Enqueue Node: {neighbor.Value.ToString()} Predecessor: {currentNode.Value.ToString()}");
}
else
{
_logger.LogTrace($"Node({neighbor.Value.ToString()}) is visited");
}
}
}
}
public void Solve(IMazeGrid maze, Action <IEnumerable <IMazeCell> > solvedResultCallback)
{
Graph <IMazeCell> graph = maze.GenerateGraph();
GraphNode <IMazeCell> startNode = (GraphNode <IMazeCell>)graph.Nodes.FindByValue(maze.Start);
Dictionary <GraphNode <IMazeCell>, GraphNode <IMazeCell> > predecessors = new Dictionary <GraphNode <IMazeCell>, GraphNode <IMazeCell> >();
List <GraphNode <IMazeCell> > nodes = new List <GraphNode <IMazeCell> >();
Dictionary <GraphNode <IMazeCell>, int> distances = new Dictionary <GraphNode <IMazeCell>, int>();
GraphNode <IMazeCell> currentNode = null;
// read all nodes and init distances
foreach (GraphNode <IMazeCell> vertex in graph.Nodes)
{
// start node has 0 distance, all over nodes are unknown and set to Max
if (vertex.Value.Equals(maze.Start))
{
distances[vertex] = 0;
}
else
{
distances[vertex] = int.MaxValue;
}
nodes.Add(vertex);
}
while (nodes.Count != 0)
{
// Find current shortest path point to explore
nodes.Sort((x, y) => distances[x] - distances[y]);
currentNode = nodes[0];
nodes.Remove(currentNode);
if (currentNode.Value.Equals(maze.Finish))
{
IEnumerable <IMazeCell> solvedPath = TraceSolvedPath(currentNode, predecessors).Reverse();
solvedResultCallback(solvedPath); // Calls the callback Action and returns the path.
break;
}
if (distances[currentNode] == int.MaxValue)
{
break;
}
foreach (GraphNode <IMazeCell> neighbor in currentNode.Neighbors)
{
var indx = currentNode.Neighbors.IndexOf(neighbor);
// distance of current node + Neighbors Cost ( Cost = paths between nodes )
int newDistance = distances[currentNode] + currentNode.Costs[indx];
if (newDistance < distances[neighbor])
{
distances[neighbor] = newDistance;
predecessors[neighbor] = currentNode;
}
}
}
}