public void Loop_from_head()
{
var node1 = new ListNode(1);
var node2 = new ListNode(2);
node2.next = node1;
node1.next = node2;
var cycleStartFinder = new LinkedListCycleStart();
Assert.Equal(node1, cycleStartFinder.DetectCycle(node1));
}
public void No_cycle()
{
var node1 = new ListNode(1);
var node2 = new ListNode(2);
var node3 = new ListNode(3);
node2.next = node3;
node1.next = node2;
var cycleStartFinder = new LinkedListCycleStart();
Assert.Null(cycleStartFinder.DetectCycle(node1));
}
public void Cycle_length_3()
{
var node1 = new ListNode(1);
var node2 = new ListNode(2);
var node3 = new ListNode(3);
var node4 = new ListNode(4);
node3.next = node4;
node2.next = node3;
node1.next = node2;
node4.next = node2;
var cycleStartFinder = new LinkedListCycleStart();
Assert.Equal(node2, cycleStartFinder.DetectCycle(node1));
}