public void ShortestPathTo_FindShortestPath_WhenThereIsPossibleMultiplePaths()
{
var graph = new DirectedWeightedSparseGraph <string>();
graph.AddVertex("a");
graph.AddVertex("b");
graph.AddVertex("c");
graph.AddVertex("d");
graph.AddEdge("a", "b", 1);
graph.AddEdge("b", "c", 1);
graph.AddEdge("c", "a", 1);
graph.AddEdge("c", "d", 1);
graph.AddEdge("b", "d", 1);
var dijkstra = new DijkstraShortestPaths <DirectedWeightedSparseGraph <string>, string>(graph, "a");
var result = dijkstra.ShortestPathTo("d");
Assert.NotNull(result);
Assert.Equal(3, result.Count());
Assert.Contains("a", result);
Assert.Contains("b", result);
Assert.Contains("d", result);
Assert.Equal(2, dijkstra.DistanceTo("d"));
}
public void DistanceTo_ReturnInfinity_WhenVertexIsNotAchievable()
{
var graph = new DirectedWeightedSparseGraph <string>();
graph.AddVertex("a");
graph.AddVertex("b");
graph.AddVertex("c");
graph.AddEdge("a", "b", 1);
var dijkstra = new DijkstraShortestPaths <DirectedWeightedSparseGraph <string>, string>(graph, "a");
Assert.Equal(long.MaxValue, dijkstra.DistanceTo("c"));
}
public void DistanceTo_Throw_WhenVertexIsNotInGraph()
{
var graph = new DirectedWeightedSparseGraph <string>();
graph.AddVertex("a");
graph.AddVertex("b");
graph.AddVertex("c");
graph.AddEdge("a", "b", 1);
var dijkstra = new DijkstraShortestPaths <DirectedWeightedSparseGraph <string>, string>(graph, "a");
Assert.Throws <ArgumentException>(() => dijkstra.DistanceTo("z"));
}
public void ShortestPathTo_FindShortestPath_WhenEdgeHaveDifferentWeight()
{
var vertices = new[] { "r", "s", "t", "x", "y", "z" };
var graph = new DirectedWeightedSparseGraph <string>();
graph.AddVertices(vertices);
graph.AddEdge("r", "s", 7);
graph.AddEdge("r", "t", 6);
graph.AddEdge("s", "t", 5);
graph.AddEdge("s", "x", 9);
graph.AddEdge("t", "x", 10);
graph.AddEdge("t", "y", 7);
graph.AddEdge("t", "z", 5);
graph.AddEdge("x", "y", 2);
graph.AddEdge("x", "z", 4);
graph.AddEdge("y", "z", 1);
var dijkstra = new DijkstraShortestPaths <DirectedWeightedSparseGraph <string>, string>(graph, "s");
var shortestToZ = dijkstra.ShortestPathTo("z");
Assert.NotNull(shortestToZ);
Assert.Equal(3, shortestToZ.Count());
Assert.Contains("s", shortestToZ);
Assert.Contains("t", shortestToZ);
Assert.Contains("z", shortestToZ);
Assert.Equal(10, dijkstra.DistanceTo("z"));
var shortestToY = dijkstra.ShortestPathTo("y");
Assert.NotNull(shortestToY);
Assert.Equal(3, shortestToY.Count());
Assert.Contains("s", shortestToY);
Assert.Contains("x", shortestToY);
Assert.Contains("y", shortestToY);
Assert.Equal(11, dijkstra.DistanceTo("y"));
}
public void LRwPathSearchTest()
{
DPNProblemContext ctx = GenerateProblemContext();
DiscreteTimeAdapter adapter = new DiscreteTimeAdapter(ctx.StartTime, ctx.EndTime, 1);
var travelgraph = new BasicTravelHyperNetwork(ctx, adapter);
travelgraph.Build();
/* Train01 Station A*/
var train = ctx.Wor.RailwayTimeTable.Trains.First();
var station = ctx.Wor.Net.StationCollection.First();
//路径集
Dictionary <CustomerArrival, List <TravelPath> > pathDict
= new Dictionary <CustomerArrival, List <TravelPath> >();
foreach (CustomerArrival c in ctx.Pal)
{
var ori = (ctx.Wor.Mar[c.Customer.MarSegID] as IRailwayMarketSegment).OriSta;
var des = (ctx.Wor.Mar[c.Customer.MarSegID] as IRailwayMarketSegment).DesSta;
var paths = DepthFirstSearcher.FindAllPaths(travelgraph,
new TravelHyperNode()
{
Time = adapter.ConvertToDiscreteTime(c.ArriveTime), Station = ori, Price = 0
},
new TravelHyperNode()
{
Time = adapter.Horizon + 1440, Station = des, Price = 0
});
pathDict.Add(c, new List <TravelPath>());
foreach (var path in paths)
{
pathDict[c].Add(new TravelPath(travelgraph, path));
}
}
//拉格朗日乘子 mu
Dictionary <CustomerArrival, Dictionary <TravelPath, decimal> > LM_mu
= new Dictionary <CustomerArrival, Dictionary <TravelPath, decimal> >();
foreach (CustomerArrival customer in ctx.Pal)
{
LM_mu.Add(customer, new Dictionary <TravelPath, decimal>());
foreach (var path in pathDict[customer])
{
LM_mu[customer].Add(path, 2);
}
}
// 拉格朗日乘子 lambda
Dictionary <IEdge <TravelHyperNode>, decimal> LM_lambda = new Dictionary <IEdge <TravelHyperNode>, decimal>();
foreach (CustomerArrival customer in ctx.Pal)
{
foreach (var path in pathDict[customer])
{
if (!LM_lambda.ContainsKey(path.ReservationArc))
{
LM_lambda.Add(path.ReservationArc, 1);
}
}
}
var graph = DpnAlgorithm.BuildLRwGraph(ctx, adapter, train, station,
pathDict,
travelgraph.LinkTrainDict,
LM_mu,
LM_lambda);
DijkstraShortestPaths <DirectedWeightedSparseGraph <string>, string> dijkstra
= new DijkstraShortestPaths <DirectedWeightedSparseGraph <string>, string>(graph,
"Start");
Assert.IsTrue(dijkstra.HasPathTo("End") == true);
var pathToC = string.Empty;
var pricepath = dijkstra.ShortestPathTo("End");
PricePath p = new PricePath(graph, pricepath);
Assert.IsTrue(p.GetWrapPoints(0.9m, 2).Count() > 0);
Assert.IsFalse(p.GetWrapPoints(1.1m, 2).Count() > 0);
foreach (var node in pricepath)
{
pathToC = String.Format("{0}({1}) -> ", pathToC, node);
}
pathToC = pathToC.TrimEnd(new char[] { ' ', '-', '>' });
Console.WriteLine("Shortest path to Station 'C': " + pathToC + "\r\n");
Assert.AreEqual(23m, Math.Round(dijkstra.DistanceTo("End")));
}
public void LRxPathSearchTest()
{
DPNProblemContext ctx = GenerateProblemContext();
CustomerArrival customer = new CustomerArrival();
DiscreteTimeAdapter adapter = new DiscreteTimeAdapter(ctx.StartTime, ctx.EndTime, 1);
TravelPath p = new TravelPath();
var graph = new LRxTravelHyperNetwork(ctx, adapter,
ObjectNetworkFactory.Create("", ctx, adapter),
customer,
new Dictionary <CustomerArrival, List <TravelPath> >()//path dict
{
{ customer, new List <TravelPath>()
{
p
} }
},
new Dictionary <IServiceSegment, decimal>()//rho
{
{ ctx.Wor.RailwayTimeTable.Trains.First().ServiceSegments.First(), 0 },
{ ctx.Wor.RailwayTimeTable.Trains.First().ServiceSegments.Last(), 0 },
{ ctx.Wor.RailwayTimeTable.Trains.Last().ServiceSegments.First(), 0 }
},
new Dictionary <CustomerArrival, Dictionary <TravelPath, decimal> >()
{
{ customer, new Dictionary <TravelPath, decimal>()
{
{ p, 1 }
} }
},//mu
new Dictionary <IEdge <TravelHyperNode>, decimal>());
graph.Build();
DijkstraShortestPaths <DirectedWeightedSparseGraph <TravelHyperNode>, TravelHyperNode> dijkstra
= new DijkstraShortestPaths <DirectedWeightedSparseGraph <TravelHyperNode>, TravelHyperNode>(graph,
new TravelHyperNode()
{
Time = 0, Station = ctx.Wor.Net.StationCollection.First(), Price = 0
});
Assert.IsTrue(dijkstra.HasPathTo(new TravelHyperNode()
{
Time = adapter.Horizon + 1440, Station = ctx.Wor.Net.StationCollection.Last(), Price = 0
}) == true);
var desNode = new TravelHyperNode()
{
Time = adapter.Horizon + 1440, Station = ctx.Wor.Net.StationCollection.Last(), Price = 0
};
var pathToC = string.Empty;
var shortestPath = dijkstra.ShortestPathTo(desNode);
foreach (var node in shortestPath)
{
pathToC = String.Format("{0}({1}) -> ", pathToC, node);
}
pathToC = pathToC.TrimEnd(new char[] { ' ', '-', '>' });
Console.WriteLine("Shortest path to Station 'C': " + pathToC + "\r\n");
Assert.AreEqual(202m, Math.Round(dijkstra.DistanceTo(desNode)));
}
