public void FloydWarshall_Smoke_Test()
{
var graph = new WeightedGraph <char, int>();
graph.AddVertex('S');
graph.AddVertex('A');
graph.AddVertex('B');
graph.AddVertex('C');
graph.AddVertex('D');
graph.AddVertex('T');
graph.AddEdge('S', 'A', 8);
graph.AddEdge('S', 'C', 10);
graph.AddEdge('A', 'B', 10);
graph.AddEdge('A', 'C', 1);
graph.AddEdge('A', 'D', 8);
graph.AddEdge('B', 'T', 4);
graph.AddEdge('C', 'D', 1);
graph.AddEdge('D', 'B', 1);
graph.AddEdge('D', 'T', 10);
var algo = new FloydWarshallShortestPath <char, int>(new FloydWarshallShortestPathOperators());
var result = algo.GetAllPairShortestPaths(graph);
var testCase = result.First(x => x.Source == 'S' && x.Destination == 'T');
Assert.AreEqual(15, testCase.Distance);
var expectedPath = new char[] { 'S', 'A', 'C', 'D', 'B', 'T' };
for (int i = 0; i < expectedPath.Length; i++)
{
Assert.AreEqual(expectedPath[i], testCase.Path[i]);
}
testCase = result.First(x => x.Source == 'T' && x.Destination == 'S');
Assert.AreEqual(15, testCase.Distance);
expectedPath = new char[] { 'T', 'B', 'D', 'C', 'A', 'S' };
for (int i = 0; i < expectedPath.Length; i++)
{
Assert.AreEqual(expectedPath[i], testCase.Path[i]);
}
}
public void Test()
{
// orientovaný ohodnocený.
var graph1 = new DirectedWeightedGraph(false);
for (int i = 'a'; i < 'h'; i++)
{
graph1.AddVertex(Convert.ToString(Convert.ToChar(i)));
}
graph1.AddEdge("a", "b", 10);
graph1.AddEdge("b", "c", 20);
graph1.AddEdge("c", "d", 3);
graph1.AddEdge("d", "e", 4);
graph1.AddEdge("f", "c", -20);
graph1.AddEdge("b", "f", 3);
graph1.AddEdge("e", "b", 10);
long[,] distances = new long[graph1.verticesCount, graph1.verticesCount];
Vertex[,] followers = new Vertex[graph1.verticesCount, graph1.verticesCount];
for (int i = 0; i < graph1.verticesCount; i++)
{
for (int j = 0; j < graph1.verticesCount; j++)
{
distances[i, j] = long.MaxValue;
followers[i, j] = null;
}
}
for (int i = 0; i < graph1.verticesCount; i++)
{
distances[i, i] = 0;
}
#region distances
// vzdálenosti z "a"
distances[0, 1] = 10;
distances[0, 2] = -7;
distances[0, 3] = -4;
distances[0, 4] = 0;
distances[0, 5] = 13;
// vzdálenosti z "b"
distances[1, 2] = -17;
distances[1, 3] = -14;
distances[1, 4] = -10;
distances[1, 5] = 3;
//vzdálenposti z "c"
distances[2, 1] = 17;
distances[2, 3] = 3;
distances[2, 4] = 7;
distances[2, 5] = 20;
//vzdálenposti z "d"
distances[3, 1] = 14;
distances[3, 2] = -3;
distances[3, 4] = 4;
distances[3, 5] = 17;
//vzdálenposti z "e"
distances[4, 1] = 10;
distances[4, 2] = -7;
distances[4, 3] = -4;
distances[4, 5] = 13;
//vzdálenposti z "f"
distances[5, 1] = -3;
distances[5, 2] = -20;
distances[5, 3] = -17;
distances[5, 4] = -13;
//"g" je nedosažitelný
#endregion
#region followers
// předchůdci k cestě z "a"
followers[0, 0] = graph1.GetVertex("a");
followers[0, 1] = graph1.GetVertex("b");
followers[0, 2] = graph1.GetVertex("b");
followers[0, 3] = graph1.GetVertex("b");
followers[0, 4] = graph1.GetVertex("b");
followers[0, 5] = graph1.GetVertex("b");
// předchůdci k cestě z "b"
followers[1, 1] = graph1.GetVertex("b");
followers[1, 2] = graph1.GetVertex("f");
followers[1, 3] = graph1.GetVertex("f");
followers[1, 4] = graph1.GetVertex("f");
followers[1, 5] = graph1.GetVertex("f");
// předchůdci k cestě z "c"
followers[2, 2] = graph1.GetVertex("c");
followers[2, 1] = graph1.GetVertex("d");
followers[2, 3] = graph1.GetVertex("d");
followers[2, 4] = graph1.GetVertex("d");
followers[2, 5] = graph1.GetVertex("d");
// předchůdci k cestě z "d"
followers[3, 3] = graph1.GetVertex("d");
followers[3, 1] = graph1.GetVertex("e");
followers[3, 2] = graph1.GetVertex("e");
followers[3, 4] = graph1.GetVertex("e");
followers[3, 5] = graph1.GetVertex("e");
// předchůdci k cestě "e"
followers[4, 4] = graph1.GetVertex("e");
followers[4, 1] = graph1.GetVertex("b");
followers[4, 2] = graph1.GetVertex("b");
followers[4, 3] = graph1.GetVertex("b");
followers[4, 5] = graph1.GetVertex("b");
// předchůdci k cestě "f"
followers[5, 5] = graph1.GetVertex("f");
followers[5, 1] = graph1.GetVertex("c");
followers[5, 2] = graph1.GetVertex("c");
followers[5, 3] = graph1.GetVertex("c");
followers[5, 4] = graph1.GetVertex("c");
//"g" je nedosažitelný
followers[6, 6] = graph1.GetVertex("g");
#endregion
var(distancesTest, followersTest) = FloydWarshallShortestPath <DirectedWeightedGraph> .Search(graph1).ToTuple();
for (int i = 0; i < graph1.verticesCount; i++)
{
for (int j = 0; j < graph1.verticesCount; j++)
{
Assert.AreEqual(distances[i, j], distancesTest[i, j]);
Assert.AreEqual(followers[i, j], followersTest[i, j]);
}
}
Stack <Vertex> path = new Stack <Vertex>();
path.Push(graph1.GetVertex("a"));
path.Push(graph1.GetVertex("b"));
path.Push(graph1.GetVertex("f"));
path.Push(graph1.GetVertex("c"));
path.Push(graph1.GetVertex("d"));
path.Push(graph1.GetVertex("e"));
Stack <Vertex> pathTest = FloydWarshallShortestPath <DirectedWeightedGraph> .GetShortestPath(graph1, "a", "e", ref followersTest);
while (path.Count > 0)
{
Assert.AreEqual(path.Pop(), pathTest.Pop());
}
}