public void BipartiteColoringOnDirectedGraphCheck()
{
var vertices = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
var graph = new DirectedALGraph <int>();
graph.AddVertices(vertices);
// Graph is:
// 1 -> 3, 4
// 1 <- 2
// 2 -> 1, 5
// 2 <- 5, 6
// 3 -> 6
// 3 <- 1
// 4 -> 6
// 4 <- 1, 5
// 5 -> 2, 4, 8
// 5 <- 2, 8
// 6 -> 2
// 6 <- 3, 4
// 7 -> 4
// 7 <- 5, 8
// 8 -> 5, 7
// 8 <- 5
// 9 ->
// 9 <-
graph.AddEdge(1, 3);
graph.AddEdge(1, 4);
graph.AddEdge(2, 1);
graph.AddEdge(2, 5);
graph.AddEdge(3, 6);
graph.AddEdge(4, 6);
graph.AddEdge(5, 2);
graph.AddEdge(5, 4);
graph.AddEdge(5, 8);
graph.AddEdge(6, 2);
graph.AddEdge(7, 4);
graph.AddEdge(8, 5);
graph.AddEdge(8, 7);
Dictionary <int, BipartiteColor> verticesColors;
Assert.IsTrue(graph.TryGetBipartiteColoring(out verticesColors));
foreach (var edge in graph.Edges)
{
Assert.IsTrue(verticesColors[edge.Source] != verticesColors[edge.Destination]);
}
// Check with not bipartite graph
graph = new DirectedALGraph <int>();
graph.AddVertices(vertices);
// Graph is:
// 1 -> 3, 4
// 1 <- 2
// 2 -> 1, 5
// 2 <- 3, 5, 6
// 3 -> 2, 6
// 3 <- 1, 4
// 4 -> 3, 6
// 4 <- 1, 7
// 5 -> 2, 7, 8
// 5 <- 2, 8
// 6 -> 2
// 6 <- 3, 4
// 7 -> 4
// 7 <- 5, 8
// 8 -> 5, 7
// 8 <- 5
// 9 ->
// 9 <-
graph.AddEdge(1, 3);
graph.AddEdge(1, 4);
graph.AddEdge(2, 1);
graph.AddEdge(2, 5);
graph.AddEdge(3, 2);
graph.AddEdge(3, 6);
graph.AddEdge(4, 3);
graph.AddEdge(4, 6);
graph.AddEdge(5, 2);
graph.AddEdge(5, 7);
graph.AddEdge(5, 8);
graph.AddEdge(6, 2);
graph.AddEdge(7, 4);
graph.AddEdge(8, 5);
graph.AddEdge(8, 7);
Assert.IsFalse(graph.TryGetBipartiteColoring(out verticesColors));
}