/// <summary>
/// Computes the shortest path between two nodes in a graph.
/// </summary>
/// <returns>Object <code>GraphRouteAlgorithmReturn</code> with the information about the path found. <code>null</code> otherwise.</returns>
public GraphRouteAlgorithmReturn ComputeShortestRoute()
{
FindShortestPath();
PredecessorData pred = predecessor.Find(p => p.Node.Equals(endNode));
if (pred != null)
{
WeightData data = weight.Find(c => c.Node.Equals(pred.Node));
if (data.Weight != int.MaxValue)
{
GraphRouteAlgorithmReturn path = new GraphRouteAlgorithmReturn();
path.Value = data.Weight;
path.Path = BuildPathCharge(predecessor, startNode, endNode);
return(path);
}
else
{
return(null);
}
}
else
{
return(null);
}
}
/// <summary>
/// Computes all routes between two nodes in a graph.
/// </summary>
/// <returns>List of <code>GraphRouteAlgorithmReturn</code> with the informations about the paths found. Empty list otherwise.</returns>
public List <GraphRouteAlgorithmReturn> ComputeAllRoutes()
{
ComputeRoutes();
List <GraphRouteAlgorithmReturn> result = new List <GraphRouteAlgorithmReturn>();
foreach (string route in routes)
{
GraphRouteAlgorithmReturn path = new GraphRouteAlgorithmReturn();
path.Value = route.Split('-').Length - 1;
path.Path = route;
result.Add(path);
}
return(result);
}
public void ComputeShortestRouteTest()
{
// arrange
string graphInfo = "AB5, BC4, CD8, DC8, DE6, AD5, CE2, EB3, AE7";
// act
GraphModel graph = GraphBusiness.BuildGraph(graphInfo);
// assert
GraphRouteAlgorithmReturn result = GraphBusiness.ComputeShortestRoute(graph, 'A', 'C');
Assert.AreEqual(9, result.Value);
Assert.AreEqual("A-B-C", result.Path);
result = GraphBusiness.ComputeShortestRoute(graph, 'B', 'B');
Assert.AreEqual(9, result.Value);
Assert.AreEqual("B-C-E-B", result.Path);
}
/// <summary>
/// Computes all routes between two nodes in a graph.
/// <param name="maxStopNumber">If <code>true</code> indicates that the algorithm will search for a route with max number of stops,
/// otherwise, algorithm will search for a route with exactly number of stops</param>
/// </summary>
/// <returns>List of <code>GraphRouteAlgorithmReturn</code> with the informations about the paths found. Empty list otherwise.</returns>
private List <GraphRouteAlgorithmReturn> ComputeAllRoutes(bool isMaxStopNumber)
{
ComputeRoutes(true);
List <GraphRouteAlgorithmReturn> result = new List <GraphRouteAlgorithmReturn>();
foreach (string route in routes)
{
GraphRouteAlgorithmReturn path = new GraphRouteAlgorithmReturn();
path.Value = route.Split('-').Length - 1; // number of stops in path
path.Path = route;
if (isMaxStopNumber || (!isMaxStopNumber && path.Value == stopNumber))
{
result.Add(path);
}
}
return(result);
}
