private DfsParenthesisVertice <T> CreateWhite(DfsVertice <T> vertice)
{
return(new DfsParenthesisVertice <T>()
{
IsWhite = true,
Timestamp = vertice.DiscoveredTimestamp,
Vertice = vertice.Vertice
});
}
private DfsParenthesisVertice <T> CreateBlack(DfsVertice <T> vertice)
{
return(new DfsParenthesisVertice <T>()
{
IsWhite = false,
Timestamp = vertice.TraversedTimestamp,
Vertice = vertice.Vertice
});
}
public bool Equals(DfsVertice <T> other)
{
var comparer = EqualityComparer <T> .Default;
return
(comparer.Equals(this.Vertice, other.Vertice) &&
comparer.Equals(this.Predescessor, other.Predescessor) &&
this.DiscoveredTimestamp == other.DiscoveredTimestamp &&
this.TraversedTimestamp == other.TraversedTimestamp);
}
public IEnumerator <DfsVertice <T> > GetEnumerator()
{
var visited = new Dictionary <T, VerticeColor>();
var stack = new Stack <DfsVertice <T> >();
var timestamp = 0;
var source = new DfsVertice <T>(_source, default(T));
source.DiscoveredTimestamp = timestamp++;
stack.Push(source);
while (stack.Count > 0)
{
var vertice = stack.Pop();
var color = VerticeColor.White;
visited.TryGetValue(vertice.Vertice, out color);
switch (color)
{
case VerticeColor.White:
visited[vertice.Vertice] = VerticeColor.Gray;
vertice.DiscoveredTimestamp = timestamp++;
stack.Push(vertice);
foreach (var adjacentVertice in _graph.GetAdjacentVertices(vertice.Vertice))
{
var adjacentColor = VerticeColor.White;
visited.TryGetValue(adjacentVertice, out adjacentColor);
if (adjacentColor == VerticeColor.White)
{
stack.Push(new DfsVertice <T>(adjacentVertice, vertice.Vertice));
}
}
break;
case VerticeColor.Gray:
visited[vertice.Vertice] = VerticeColor.Black;
stack.Push(vertice);
break;
case VerticeColor.Black:
vertice.TraversedTimestamp = timestamp++;
yield return(vertice);
break;
}
}
}
