/// <summary>
/// Calculates the edge set from the adjacency information stored in the GraphNodes of the current search space.
/// </summary>
private GraphEdgeSet ComputeEdges()
{
var edgeSet = new GraphEdgeSet(_nodeStates.SearchSpaceSize);
// Go through all nodes and their neigbors ...
foreach (var node in _nodeStates.SearchSpace)
{
foreach (var neighbor in node.Adjacent)
{
var current = neighbor;
var previous = node;
var path = new HashSet <ushort>();
// Skip nodes with degree 2 that are not target nodes and instead traverse through them.
while (current.Adjacent.Count == 2 && (current.DistancesIndex < 0 || !_nodeStates.IsTarget(current.DistancesIndex)))
{
path.Add(current.Id);
var tmp = current;
// Because the current node has degree 2, there is exactly one node adjacent that is not the previous one.
current = current.Adjacent.First(n => n != previous);
previous = tmp;
}
// Now create an edge if
// - current is in the search space
// - the edge is not reflexive
// - the edge is the shortest path between both nodes
if (current.DistancesIndex >= 0 && node != current &&
path.SetEquals(_data.DistanceLookup.GetShortestPath(node.DistancesIndex, current.DistancesIndex)))
{
edgeSet.Add(node.DistancesIndex, current.DistancesIndex,
_data.DistanceLookup[node.DistancesIndex, current.DistancesIndex]);
}
}
}
return(edgeSet);
}
/// <summary>
/// Calculates the edge set from the adjacency information stored in the GraphNodes of the current search space.
/// </summary>
private GraphEdgeSet ComputeEdges()
{
var edgeSet = new GraphEdgeSet(_nodeStates.SearchSpaceSize);
// Go through all nodes and their neigbors ...
foreach (var node in _nodeStates.SearchSpace)
{
foreach (var neighbor in node.Adjacent)
{
var current = neighbor;
var previous = node;
var path = new HashSet<ushort>();
// Skip nodes with degree 2 that are not target nodes and instead traverse through them.
while (current.Adjacent.Count == 2 && (current.DistancesIndex < 0 || !_nodeStates.IsTarget(current.DistancesIndex)))
{
path.Add(current.Id);
var tmp = current;
// Because the current node has degree 2, there is exactly one node adjacent that is not the previous one.
current = current.Adjacent.First(n => n != previous);
previous = tmp;
}
// Now create an edge if
// - current is in the search space
// - the edge is not reflexive
// - the edge is the shortest path between both nodes
if (current.DistancesIndex >= 0 && node != current &&
path.SetEquals(_data.DistanceLookup.GetShortestPath(node.DistancesIndex, current.DistancesIndex)))
{
edgeSet.Add(node.DistancesIndex, current.DistancesIndex,
_data.DistanceLookup[node.DistancesIndex, current.DistancesIndex]);
}
}
}
return edgeSet;
}
