/// <summary>
/// Try and find cycles through the triple formed from <paramref name="v"/> and any two
/// of it's neighbours.
/// </summary>
/// <param name="v">a vertex in the graph</param>
private void FindTriple(int v)
{
int[] ws = graph[v];
int deg = ws.Length;
// disconnect 'v' from its neighbors 'ws'
Disconnect(ws, v);
// for every pair of neighbors (u,w) connected to v try and find the
// shortest path that doesn't travel through 'v'. If a path can be found
// this is the shortest cycle through the three vertices '-u-v-w-'
// where u = ws[i] and w = ws[j]
for (int i = 0; i < deg; i++)
{
ShortestPaths sp = new ShortestPaths(graph, null, ws[i]);
for (int j = i + 1; j < deg; j++)
{
// ignore if there is an exciting cycle through the the triple
if (canonical && Exists(ws[i], v, ws[j]))
{
continue;
}
// if there is a path between u and w, form a cycle by appending
// v and storing in the basis
if (sp.GetNPathsTo(ws[j]) > 0)
{
// canonic, use the a shortest path (dependant on vertex
// order) - non-canonic, use all possible shortest paths
int[][] paths = canonical ? new int[][] { sp.GetPathTo(ws[j]) } : sp.GetPathsTo(ws[j]);
foreach (var path in paths)
{
basis.Add(new Path(Append(path, v)));
}
}
}
}
Reconnect(ws, v);
}
void Main()
{
{
#region
IAtomContainer benzene = TestMoleculeFactory.MakeBenzene();
IAtom c1 = benzene.Atoms[0];
IAtom c4 = benzene.Atoms[3];
// shortest paths from C1
ShortestPaths sp = new ShortestPaths(benzene, c1);
// number of paths from C1 to C4
int nPaths = sp.GetNPathsTo(c4);
// distance between C1 to C4
int distance = sp.GetDistanceTo(c4);
// reconstruct a path to the C4 - determined by storage order
int[] path = sp.GetPathTo(c4);
// reconstruct all paths
int[][] paths = sp.GetPathsTo(c4);
int[] org = paths[0]; // paths[0] == path
int[] alt = paths[1];
#endregion
}
{
IAtomContainer benzene = TestMoleculeFactory.MakeBenzene();
IAtom c1 = benzene.Atoms[0];
#region GetPathTo_int
ShortestPaths sp = new ShortestPaths(benzene, c1);
// reconstruct first path
int[] path = sp.GetPathTo(5);
// check there is only one path
if (sp.GetNPathsTo(5) == 1)
{
path = sp.GetPathTo(5); // reconstruct the path
}
#endregion
}
{
IAtomContainer benzene = TestMoleculeFactory.MakeBenzene();
IAtom c1 = benzene.Atoms[0];
#region GetPathTo_IAtom
ShortestPaths sp = new ShortestPaths(benzene, c1);
IAtom end = benzene.Atoms[3];
// reconstruct first path
int[] path = sp.GetPathTo(end);
// check there is only one path
if (sp.GetNPathsTo(end) == 1)
{
path = sp.GetPathTo(end); // reconstruct the path
}
#endregion
}
{
IAtomContainer benzene = TestMoleculeFactory.MakeBenzene();
IAtom c1 = benzene.Atoms[0];
#region GetPathsTo_int
int threshold = 20;
ShortestPaths sp = new ShortestPaths(benzene, c1);
// reconstruct shortest paths
int[][] paths = sp.GetPathsTo(5);
// only reconstruct shortest paths below a threshold
if (sp.GetNPathsTo(5) < threshold)
{
int[][] path = sp.GetPathsTo(5); // reconstruct shortest paths
}
#endregion
}
{
IAtomContainer benzene = TestMoleculeFactory.MakeBenzene();
IAtom c1 = benzene.Atoms[0];
#region GetPathsTo_IAtom
int threshold = 20;
ShortestPaths sp = new ShortestPaths(benzene, c1);
IAtom end = benzene.Atoms[3];
// reconstruct all shortest paths
int[][] paths = sp.GetPathsTo(end);
// only reconstruct shortest paths below a threshold
if (sp.GetNPathsTo(end) < threshold)
{
paths = sp.GetPathsTo(end); // reconstruct shortest paths
}
#endregion
}
{
IAtomContainer benzene = TestMoleculeFactory.MakeBenzene();
IAtom c1 = benzene.Atoms[0];
#region GetAtomsTo_int
ShortestPaths sp = new ShortestPaths(benzene, c1);
// reconstruct a shortest path
IAtom[] path = sp.GetAtomsTo(5);
// ensure single shortest path
if (sp.GetNPathsTo(5) == 1)
{
path = sp.GetAtomsTo(5); // reconstruct shortest path
}
#endregion
}
{
IAtomContainer benzene = TestMoleculeFactory.MakeBenzene();
IAtom c1 = benzene.Atoms[0];
#region GetAtomsTo_IAtom
ShortestPaths sp = new ShortestPaths(benzene, c1);
IAtom end = benzene.Atoms[3];
// reconstruct a shortest path
IAtom[] path = sp.GetAtomsTo(end);
// ensure single shortest path
if (sp.GetNPathsTo(end) == 1)
{
path = sp.GetAtomsTo(end); // reconstruct shortest path
}
#endregion
}
{
IAtomContainer benzene = TestMoleculeFactory.MakeBenzene();
IAtom c1 = benzene.Atoms[0];
#region GetNPathsTo_int
ShortestPaths sp = new ShortestPaths(benzene, c1);
sp.GetNPathsTo(5); // number of paths
sp.GetNPathsTo(-1); // returns 0 - there are no paths
#endregion
}
{
IAtomContainer benzene = TestMoleculeFactory.MakeBenzene();
IAtom c1 = benzene.Atoms[0];
#region GetNPathsTo_IAtom
ShortestPaths sp = new ShortestPaths(benzene, c1);
IAtom end = benzene.Atoms[3];
sp.GetNPathsTo(end); // number of paths
sp.GetNPathsTo(null); // returns 0 - there are no paths
sp.GetNPathsTo(new Atom("C")); // returns 0 - there are no paths
#endregion
}
{
#region GetDistanceTo_int_1
IAtomContainer container = TestMoleculeFactory.MakeBenzene();
IAtom c1 = container.Atoms[0];
ShortestPaths sp = new ShortestPaths(container, c1); // start = 0
int n = container.Atoms.Count;
if (sp.GetDistanceTo(5) < n)
{
// these is a path from 0 to 5
}
#endregion
}
{
#region GetDistanceTo_int_2
IAtomContainer container = TestMoleculeFactory.MakeBenzene();
IAtom c1 = container.Atoms[0];
ShortestPaths sp = new ShortestPaths(container, c1); // start = 0
int[] path = sp.GetPathTo(5);
int start = path[0];
int end = path[sp.GetDistanceTo(5)];
#endregion
}
{
#region GetDistanceTo_IAtom_1
IAtomContainer container = TestMoleculeFactory.MakeBenzene();
IAtom c1 = container.Atoms[0];
ShortestPaths sp = new ShortestPaths(container, c1); // start atom
IAtom end = container.Atoms[3];
int n = container.Atoms.Count;
if (sp.GetDistanceTo(end) < n)
{
// these is a path from start to end
}
#endregion
}
{
#region GetDistanceTo_IAtom_2
IAtomContainer container = TestMoleculeFactory.MakeBenzene();
IAtom c1 = container.Atoms[0];
ShortestPaths sp = new ShortestPaths(container, c1); // start atom
IAtom end = container.Atoms[3];
IAtom[] atoms = sp.GetAtomsTo(end);
Console.WriteLine(end == atoms[sp.GetDistanceTo(end)]); // true
#endregion
}
}
