def to_linked_list(s: str) -> Node:
head = Node(s[0])
tail = s[1:]
p = head
for c in tail:
current = Node(c)
p.next = current
p = current
return head
def test_node(self):
# can be instantiated
head = Node('head')
self.assertTrue(head.next == None)
self.assertTrue(head.record == 'head')
# can set pointer to next
next = Node('next')
head.set_next(next)
self.assertTrue(head.next == next)
def remove(head: Node, to_remove: Node) -> Node:
"""
Remove a node from the middle of a list given only the pointer to that node
"Absorb" the next node into the node to be removed. Then simply skip
the next node.
"""
temp: Node = to_remove.next
to_remove.record = temp.record
to_remove.set_next(temp.next)
return head
def test_linked_list(self):
first = Node('first')
second = Node('second')
third = Node('third')
first.next = second
second.next = third
self.assertTrue(first.next == second)
self.assertTrue(second.next == third)
print("No cycle found")
return
if visited.__contains__(n):
print('Found cycle at {}'.format(n.record))
return
if n is not None:
visited.append(n)
recurse(access_next(n), visited)
# Test cycle
print("Testing cycle...")
repeated = Node('c')
e = Node('e')
e.set_next(repeated)
d = Node('d')
d.set_next(e)
repeated.set_next(d)
b = Node('b')
b.set_next(repeated)
a = Node('a')
a.set_next(b)
recurse(a)
# Test no cycle
print("Testing no cycle...")
c = Node('c')
b = Node('b')
def setUp(self):
self.a = Node('a')
self.b = Node('b')
self.c = Node('c')
self.d = Node('d')
self.e = Node('e')
class TestTwoSix(unittest.TestCase):
def setUp(self):
self.a = Node('a')
self.b = Node('b')
self.c = Node('c')
self.d = Node('d')
self.e = Node('e')
def test_find_cycle(self):
self.a.set_next(self.b)
self.b.set_next(self.c)
self.c.set_next(self.d)
self.d.set_next(self.e)
self.e.set_next(self.c)
head = self.a
cycle = self.c
self.assertEqual(tester.find_cycle(head), cycle)
def test_no_cycle(self):
self.a.set_next(self.b)
self.b.set_next(self.c)
self.c.set_next(self.d)
self.d.set_next(self.e)
self.assertEqual(tester.find_cycle(self.a), None)