public IEnumerator <BfsVertice <T> > GetEnumerator()
{
var visited = new HashSet <T>();
var queue = new Queue <BfsVertice <T> >();
// NOTE: questionable usage of default(T) - it is not meaningful for non-reference types, especially for integers
queue.Enqueue(new BfsVertice <T>(_source, default(T), 0));
while (queue.Count > 0)
{
var bfsVertice = queue.Dequeue();
if (!visited.Contains(bfsVertice.Vertice))
{
visited.Add(bfsVertice.Vertice);
foreach (var adjacentVertice in _graph.GetAdjacentVertices(bfsVertice.Vertice))
{
queue.Enqueue(new BfsVertice <T>(adjacentVertice, bfsVertice.Vertice, bfsVertice.Distance + 1));
}
}
yield return(bfsVertice);
}
}
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;
}
}
}