python判断链表是否有环
为啥一定会相遇呢,可以看这个:为什么用快慢指针找链表的环,快指针和慢指针一定会相遇?
代码:
def has_cycle(self):
fast, low = self._head, self._head
while fast and fast.next:
low = low.next
fast = fast.next.next
if low == fast:
return True
return False