public override int Execute()
{
if (queue.Count == 0)
{
IsFinished = true; // search ended, node has not been found
return(-1);
}
int node = queue.Dequeue();
List <int> adjacentNodes = graph.GetAdjacentNodes(node);
bool allVisited = true;
foreach (var i in adjacentNodes)
{
if (!visited.Contains(i))
{
queue.Enqueue(i);
visited.Add(i);
allVisited = false;
}
}
if (allVisited)
{
OnAllChildrenVisited?.Invoke(node);
OnHasNoChildren?.Invoke(node); // same thing in BFS
}
return(node); // return current node
}
public GraphEnumerator(Graph g, TraversalStrategyEnum ts = TraversalStrategyEnum.BFS)
{
graph = g ?? throw new NullReferenceException("The enumerable graph cannot be null.");
version = g.Version;
switch (ts)
{
case TraversalStrategyEnum.BFS:
{
strategy = new TraversalStrategyBFS(graph);
break;
}
case TraversalStrategyEnum.DFS:
{
strategy = new TraversalStrategyDFS(graph);
break;
}
}
// if strategy's event fires, fire ours
strategy.OnAllChildrenVisited += delegate(int nodeIndex)
{
OnAllChildrenVisited?.Invoke(nodeIndex);
};
strategy.OnHasNoChildren += delegate(int nodeIndex)
{
OnHasNoChildren?.Invoke(nodeIndex);
};
}
public override int Execute()
{
while (true)
{
if (stack.Count == 0) // if stack is empty traversal is over
{
IsFinished = true;
return(-1);
}
int node = stack.Pop();
if (!visited.Contains(node)) // we haven't been here before
{
visited.Add(node); // mark as visited
if (HasChildren(node))
{
stack.Push(node);
List <int> adjacentNodes = graph.GetAdjacentNodes(node);
foreach (var i in adjacentNodes) // push all children on stack
{
if (!visited.Contains(i))
{
stack.Push(i);
}
}
}
else
{
OnHasNoChildren?.Invoke(node);
}
return(node);
}
else
{
if (!allChildrenVisited.Contains(node))
{
OnAllChildrenVisited?.Invoke(node);
allChildrenVisited.Add(node);
}
}
}
}
