public void TestDijkstra()
{
// 0 -- 1 -- 2 -- 3
// \ | /
// \ | /
// 4 -- 5
bool[,] graph =
{
{ false, true, false, false, true, false },
{ true, false, true, false, false, false },
{ false, true, false, true, false, true },
{ false, false, true, false, false, true },
{ true, false, false, false, false, true },
{ false, false, true, true, true, false },
};
var searchGraph = SearchGraphFromData(graph);
var graphNodes = GetGraphNodesIdIndex(searchGraph);
var distanceLookup = new DistanceLookup(graphNodes.Values.ToList());
Assert.AreEqual((uint)0, distanceLookup[graphNodes[0].DistancesIndex, graphNodes[0].DistancesIndex],
"Failed 0 distance test");
Assert.AreEqual((uint)2, distanceLookup[graphNodes[0].DistancesIndex, graphNodes[5].DistancesIndex],
"Wrong distance");
Assert.AreEqual((uint)3, distanceLookup[graphNodes[0].DistancesIndex, graphNodes[3].DistancesIndex],
"Wrong distance");
}
public void DijkstraUnconnected()
{
// 0 -- 1 2 -- 3
// | /
// | /
// 4 -- 5
bool[,] graph =
{
{ false, true, false, false, false, false },
{ true, false, false, false, false, false },
{ false, false, false, true, false, true },
{ false, false, true, false, false, true },
{ false, false, false, false, false, true },
{ false, false, true, true, true, false },
};
var searchGraph = SearchGraphFromData(graph);
var graphNodes = GetGraphNodesIdIndex(searchGraph);
var mstNodes = new List <GraphNode> {
graphNodes[0], graphNodes[2], graphNodes[4], graphNodes[3]
};
var distances = new DistanceLookup(graphNodes.Values.ToArray());
Assert.IsNull(distances.GetShortestPath(mstNodes[0].DistancesIndex, mstNodes[3].DistancesIndex));
}
public SteinerPreprocessorResult(
IReadOnlyList <GraphNode> fixedTargetNodes, GraphNode startNode, IReadOnlyList <GraphNode> remainingNodes,
DistanceLookup distanceLookup, ShortestPathLookup shortestPathLookup)
{
FixedTargetNodes = fixedTargetNodes;
StartNode = startNode;
RemainingNodes = remainingNodes;
DistanceLookup = distanceLookup;
ShortestPathLookup = shortestPathLookup;
}
public void TestMST()
{
// 0 -- 1 -- 2 -- 3
// \ | /
// \ | /
// 4 -- 5 -- 6 -- 7
bool[,] graph =
{
{ false, true, false, false, true, false, false, false },
{ true, false, true, false, false, false, false, false },
{ false, true, false, true, false, true, false, false },
{ false, false, true, false, false, true, false, false },
{ true, false, false, false, false, true, false, false },
{ false, false, true, true, true, false, true, false },
{ false, false, false, false, false, true, false, true },
{ false, false, false, false, false, false, true, false },
};
var searchGraph = SearchGraphFromData(graph);
var graphNodes = GetGraphNodesIdIndex(searchGraph);
var mstNodes = new List <GraphNode>
{
graphNodes[3], graphNodes[5], graphNodes[7], graphNodes[0]
};
var distances = new DistanceLookup(mstNodes);
var mst = new MinimalSpanningTree(mstNodes.Select(n => n.DistancesIndex).ToList(), distances);
mst.Span(graphNodes[0].DistancesIndex);
Assert.AreEqual(3, mst.SpanningEdges.Count, "Wrong amount of spanning edges");
var goalEdges = new[]
{
new[] { 0, 5 }, new[] { 5, 3 }, new[] { 5, 7 }
};
foreach (var edge in goalEdges)
{
Assert.AreEqual(1,
mst.SpanningEdges.Select(
e => new Tuple <ushort, ushort>(distances.IndexToNode(e.Inside).Id,
distances.IndexToNode(e.Outside).Id)).Count(
t =>
(t.Item1 == edge[0] && t.Item2 == edge[1]) ||
(t.Item1 == edge[1] && t.Item2 == edge[0])),
"Edge " + edge + " not contained exactly once.");
}
}
/// <summary>
/// Instantiates a new MinimalSpanningTree.
/// </summary>
/// <param name="mstNodes">The GraphNodes that should be spanned. (not null)</param>
/// <param name="distances">The DistanceLookup used as cache.</param>
public MinimalSpanningTree(IReadOnlyList <int> mstNodes, DistanceLookup distances)
{
_mstNodes = mstNodes ?? throw new ArgumentNullException(nameof(mstNodes));
_distances = distances;
}