def get_next(self):
"""Test get_next method."""
n1 = Node(1)
n2 = Node(2)
# by default, next is None
self.assertIsNone(n1.next)
n1.set_next(n2)
self.assertEqual(n1.get_next(), n2)
def set_next(self):
"""Test set_next method."""
n1 = Node(1)
n2 = Node(2)
# by default, next is None
self.assertIsNone(n1.next)
n1.set_next(n2)
# data from next is data from node 2
self.assertEqual(n1.get_next().get_data(), 2)
def returnbeginning(n1):
fast = n1
slow = n1
while fast.get_next() is not None and slow.get_next() is not None:
fast = fast.get_next().get_next()
slow = slow.get_next()
if fast is slow:
break
fast = n1
while True:
if fast is slow:
return slow
else:
fast = fast.get_next()
slow = slow.get_next()
n8 = Node(8)
n7 = Node(7, n8)
n6 = Node(6, n7)
n5 = Node(5, n6)
n4 = Node(4, n5)
n3 = Node(3, n4)
n8.set_next(n3)
n2 = Node(2, n3)
n1 = Node(1, n2)
print returnbeginning(n1).get_data()
