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有人可以告诉我证明链表包含循环的最佳方法吗? 我使用的是一种带有两个指针的算法,一个是缓慢移动一步,一个是快速移动两步。
class Node(object):
def __init__(self, value, next=None):
self.next=next
self.value=value
def create_list():
last = Node(8)
head = Node(7, last)
head = Node(6, head)
head = Node(5, head)
head = Node(4, head)
head = Node(3, head)
head = Node(2, head)
head = Node(1, head)
last.next = head
return head
def is_circular(head):
slow = head
fast = head
while True:
slow = slow.next
fast = fast.next.next
print slow.value, fast.value
if slow.value == fast.value:
return True
elif slow is fast:
return False
if __name__ == "__main__":
node = create_list()
print is_circular(node)