public void Graph_StartDFSInTheMiddle_ReturnCycleOfTwo()
{
// Arrange
var graph = new DirectGraph <GraphNode>();
var node1 = new GraphNode();
var node2 = new GraphNode();
var node3 = new GraphNode();
node1.LinkNext(node2);
node2.LinkNext(node3);
graph.Add("node1", node1);
graph.Add("node2", node2);
graph.Add("node3", node2);
// Act
var cycles = new List <Cycle <GraphNode> >();
foreach (var cycle in graph.DepthFirstCycle(node2))
{
cycles.Add(cycle);
}
// Assert
Assert.AreEqual(1, cycles.Count);
var cycle1 = cycles[0];
Assert.AreEqual(2, cycle1.Count);
Assert.AreEqual(node2, cycle1[0]);
Assert.AreEqual(node3, cycle1[1]);
}
public void Graph_AddInfiniteRelation_ReturnNoCycles()
{
// Arrange
var graph = new DirectGraph <GraphNode>();
var node1 = new GraphNode();
var node2 = new GraphNode();
node1.LinkNext(node2);
node2.LinkNext(node1);
graph.Add("node1", node1);
graph.Add("node2", node2);
// Act
var cycles = new List <Cycle <GraphNode> >();
foreach (var cycle in graph.DepthFirstCycle(node1))
{
cycles.Add(cycle);
}
// Assert
Assert.IsTrue(graph.IsCyclic);
Assert.AreEqual(0, cycles.Count);
}
public void Graph_AddBackEdge_BypassInfiniteLoop_ReturnOneCycle()
{
// Arrange
var graph = new DirectGraph <GraphNode>();
var node1 = new GraphNode {
Name = "node1"
};
var node2 = new GraphNode {
Name = "node2"
};
var node3 = new GraphNode {
Name = "node3"
};
var node4 = new GraphNode {
Name = "node4"
};
var node5 = new GraphNode {
Name = "node5"
};
// Arrange - setup relations
node1.LinkNext(node2);
node2.LinkNext(node5);
node1.LinkNext(node3);
node3.LinkNext(node4);
node4.LinkNext(node1);
graph.Add("node1", node1);
graph.Add("node2", node2);
graph.Add("node3", node3);
graph.Add("node4", node4);
graph.Add("node5", node5);
// Act
var cycles = new List <Cycle <GraphNode> >();
foreach (var cycle in graph.DepthFirstCycle(node1))
{
cycles.Add(cycle);
}
// Assert
Assert.IsTrue(graph.IsCyclic);
Assert.AreEqual(1, cycles.Count);
var cycle1 = cycles[0];
Assert.AreEqual(3, cycle1.Count);
Assert.AreEqual(1, cycle1.Number);
Assert.AreEqual(node1, cycle1[0], "node1");
Assert.AreEqual(node2, cycle1[1], "node2");
Assert.AreEqual(node5, cycle1[2], "node5");
}
public void Graph_CreateTwoCycleValidGraph_ReturnTwoCycles()
{
// Arrange
var graph = new DirectGraph <GraphNode>();
var node1 = new GraphNode();
var node2 = new GraphNode();
var node3 = new GraphNode();
var node4 = new GraphNode();
// Arrange - setup relations
node1.LinkNext(node2);
node1.LinkNext(node3);
node2.LinkNext(node4);
node3.LinkNext(node4);
graph.Add("node1", node1);
graph.Add("node2", node2);
graph.Add("node3", node3);
graph.Add("node4", node4);
// Act
var cycles = new List <Cycle <GraphNode> >();
foreach (var cycle in graph.DepthFirstCycle(node1))
{
cycles.Add(cycle);
}
// Assert
Assert.AreEqual(2, cycles.Count);
var cycle1 = cycles[0];
Assert.AreEqual(1, cycle1.Number);
Assert.AreEqual(node1, cycle1[0]);
Assert.AreEqual(node3, cycle1[1]);
Assert.AreEqual(node4, cycle1[2]);
var cycle2 = cycles[1];
Assert.AreEqual(2, cycle2.Number);
Assert.AreEqual(node1, cycle2[0]);
Assert.AreEqual(node2, cycle2[1]);
Assert.AreEqual(node4, cycle2[2]);
}