public void TestDijkstra()
{
// 0 -- 1 -- 2 -- 3
// \ | /
// \ | /
// 4 -- 5
bool[,] graph1 = {
{ 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 },
};
SearchGraph searchGraph1 = SearchGraphFromData(graph1);
Dictionary<int, GraphNode> graphNodes = GetGraphNodesIdIndex(searchGraph1);
DistanceLookup 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");
}
/// <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.
/// <see cref="DistanceLookup.CalculateFully"/> must have been called. (not null</param>
public MinimalSpanningTree(List <GraphNode> mstNodes, DistanceLookup distances)
{
if (mstNodes == null)
{
throw new ArgumentNullException("mstNodes");
}
if (distances == null)
{
throw new ArgumentNullException("distances");
}
if (!distances.FullyCached)
{
throw new ArgumentException("CalculateFully must have been called.", "distances");
}
// Copy might be preferable, doesn't really matter atm though.
_mstNodes = mstNodes;
_distances = distances;
IsSpanned = false;
}
public void DijkstraUnconnected()
{
// 0 -- 1 2 -- 3
// | /
// | /
// 4 -- 5
bool[,] graph2 =
{
{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},
};
SearchGraph searchGraph2 = SearchGraphFromData(graph2);
Dictionary<int, GraphNode> graphNodes2 = GetGraphNodesIdIndex(searchGraph2);
var mstNodes2 = new List<GraphNode> { graphNodes2[0], graphNodes2[2], graphNodes2[4], graphNodes2[3] };
var distances = new DistanceLookup(graphNodes2.Values.ToArray());
Assert.IsNull(distances.GetShortestPath(mstNodes2[0].DistancesIndex, mstNodes2[3].DistancesIndex));
}
public void TestMST()
{
// 0 -- 1 -- 2 -- 3
// \ | /
// \ | /
// 4 -- 5 -- 6 -- 7
bool[,] graph1 = {
{ 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 },
};
SearchGraph searchGraph1 = SearchGraphFromData(graph1);
Dictionary<int, GraphNode> graphNodes1 = GetGraphNodesIdIndex(searchGraph1);
var mstNodes1 = new List<GraphNode>
{ graphNodes1[3], graphNodes1[5], graphNodes1[7], graphNodes1[0] };
var distances = new DistanceLookup(mstNodes1);
var mst1 = new MinimalSpanningTree(mstNodes1.Select(n => n.DistancesIndex).ToList(), distances);
mst1.Span(graphNodes1[0].DistancesIndex);
Assert.AreEqual(3, mst1.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,
mst1.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.");
}
}