27 lines
470 B
Python
27 lines
470 B
Python
|
import random
|
||
|
|
|
||
|
|
from linked_list import Node
|
||
|
|
|
||
|
|
def contains_cycle(node):
|
||
|
|
one = node
|
||
|
|
two = node
|
||
|
|
while two.next and two.next.next:
|
||
|
|
one = one.next
|
||
|
|
two = two.next.next
|
||
|
|
if one == two:
|
||
|
|
return True
|
||
|
|
return False
|
||
|
|
|
||
|
|
xs = Node(1, Node(2, Node(3)))
|
||
|
|
assert not contains_cycle(xs)
|
||
|
|
print("Success!")
|
||
|
|
|
||
|
|
a = Node(1)
|
||
|
|
b = Node(2)
|
||
|
|
c = Node(3)
|
||
|
|
a.next = b
|
||
|
|
b.next = c
|
||
|
|
c.next = random.choice([a, b, c])
|
||
|
|
assert contains_cycle(a)
|
||
|
|
print("Success!")
|