public void FindCircularStartNodeInplaceTest_FullCycle()
{
var testList = new LinkedList(new LinkedListNode(1)
{
Next = new LinkedListNode(2)
{
Next = new LinkedListNode(3)
{
Next = new LinkedListNode(4)
{
Next = new LinkedListNode(5)
{
Next = new LinkedListNode(6)
}
}
}
}
});
testList.Head.Next.Next.Next.Next.Next.Next = testList.Head;
LinkedListNode resultNode = Question_2_8.FindCircularStartNodeInplace(testList);
Assert.IsNotNull(resultNode, "List is not circular.");
Assert.AreEqual(testList.Head, resultNode, $"Incorrect circular start node {testList.Head.Data} (expected) vs {resultNode.Data} (actual).");
}
public void FindCircularStartNodeTest_NegativeCase()
{
var testList = new LinkedList(new int[] { 1, 2, 3, 4, 5, 3 });
LinkedListNode resultNode = Question_2_8.FindCircularStartNode(testList);
int resultData = (resultNode != null) ? resultNode.Data : -1;
Assert.IsNull(resultNode, $"List is circular starting at node {resultData}.");
testList = new LinkedList(new int[] { 1, 2, 3, 4, 5, 6, 3 });
resultNode = Question_2_8.FindCircularStartNode(testList);
resultData = (resultNode != null) ? resultNode.Data : -1;
Assert.IsNull(resultNode, $"List is circular starting at node {resultData}.");
}
public void FindCircularStartNodeTest_PositiveCase()
{
var circularStartNode = new LinkedListNode(3)
{
Next = new LinkedListNode(4)
{
Next = new LinkedListNode(5)
}
};
circularStartNode.Next.Next.Next = circularStartNode;
var testList = new LinkedList(new LinkedListNode(1)
{
Next = new LinkedListNode(2)
{
Next = circularStartNode
}
});
LinkedListNode resultNode = Question_2_8.FindCircularStartNode(testList);
Assert.IsNotNull(resultNode, "List is not circular.");
Assert.AreEqual(circularStartNode, resultNode, $"Incorrect circular start node {circularStartNode.Data} (expected) vs {resultNode.Data} (actual).");
}
private static void Validate <T>(Node <T> expected, Node <T> list)
where T : IEquatable <T>
{
Assert.AreEqual(expected, Question_2_8.BeginningOfCycle(list));
}
public void Question_2_8_InvalidCases()
{
TestHelpers.AssertExceptionThrown(() => Question_2_8.BeginningOfCycle <int>(null), typeof(ArgumentNullException));
}
