private int DFS(HashSet <string> clay, Node spring, int ymax, int ymin, Dictionary <string, Node> seen)
{
var stack = new StackSet <Node>();
stack.Push(spring);
var answer = 0;
while (stack.Any())
{
var current = stack.Pop();
seen[current.Location.Hash] = current;
if (current.Location.Y <= ymax && current.Location.Y >= ymin && !current.Visited)
{
current.Visited = true;
answer++;
}
if (current.Location.Y > ymax)
{
MarkFlowing(current, stack, clay, seen);
continue;
}
PrintArea(stack, clay, seen, current, false);
// down
if (!clay.Contains(current.Location.Down.Hash))
{
if (!seen.ContainsKey(current.Location.Down.Hash))
{
var node = new Node(current.Location.Down, current);
stack.Push(node);
continue;
}
else if (seen[current.Location.Down.Hash].Flowing)
{
MarkFlowing(current, stack, clay, seen);
continue;
}
}
var leftAdded = false;
var rightAdded = false;
// check left
if (!clay.Contains(current.Location.Left.Hash))
{
if (!seen.ContainsKey(current.Location.Left.Hash))
{
var newLeft = new Node(current.Location.Left, current)
{
Right = current
};
current.Left = newLeft;
stack.Push(newLeft);
leftAdded = true;
}
else if (seen[current.Location.Left.Hash].Flowing)
{
current.Flowing = true;
}
}
// check Right
if (!clay.Contains(current.Location.Right.Hash))
{
if (!seen.ContainsKey(current.Location.Right.Hash))
{
var newRight = new Node(current.Location.Right, current)
{
Left = current
};
current.Right = newRight;
stack.Push(newRight);
rightAdded = true;
}
else if (seen[current.Location.Right.Hash].Flowing)
{
current.Flowing = true;
}
}
if (!leftAdded && !rightAdded && current.Previous != null)
{
stack.Push(current.Previous);
}
}
return(answer);
}