public void ForestCyclesCheck() { var vertices = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }; var graph = new WeightedALGraph <int, int>(); graph.AddVertices(vertices); // Graph is: // first component // 1 <-> 2, 3, 4 // 2 <-> 1, 3, 5, 6 // 3 <-> 1, 2, 6 // 4 <-> 1, 6, 7 // 5 <-> 2, 7, 8 // 6 <-> 2, 3, 4 // 7 <-> 4, 8 // 8 <-> 7, 5 // second component // 9 <-> 10, 12 // 10 <-> 9, 11, 12 // 11 <-> 10, 12, 13 // 12 <-> 9, 10, 11 // 13 <-> 11 // third component // 14 <-> 15, 16 // 15 <-> 14, 16 // 16 <-> 14, 15 // With each edge having a weight of the absolute value of the difference of the vertices graph.AddEdge(1, 2, 1); graph.AddEdge(1, 3, 2); graph.AddEdge(1, 4, 3); graph.AddEdge(2, 3, 1); graph.AddEdge(2, 5, 3); graph.AddEdge(2, 6, 4); graph.AddEdge(3, 6, 3); graph.AddEdge(4, 6, 2); graph.AddEdge(4, 7, 3); graph.AddEdge(5, 7, 2); graph.AddEdge(5, 8, 3); graph.AddEdge(7, 8, 1); graph.AddEdge(9, 10, 1); graph.AddEdge(9, 12, 3); graph.AddEdge(10, 11, 1); graph.AddEdge(10, 12, 2); graph.AddEdge(11, 12, 1); graph.AddEdge(11, 13, 2); graph.AddEdge(14, 15, 1); graph.AddEdge(14, 16, 2); graph.AddEdge(15, 16, 1); // Graph has to be cyclic Assert.IsTrue(graph.IsCyclic()); // Compute MST of the graph var mst = graph.KruskalMST(); // The MST is acyclic Assert.IsFalse(mst.IsCyclic()); }