21 lines
569 B
Python
21 lines
569 B
Python
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# Definition for singly-linked list.
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class ListNode:
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def __init__(self, x):
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self.val = x
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self.next = None
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# Definition for singly-linked list.
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# class ListNode:
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# def __init__(self, x):
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# self.val = x
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# self.next = None
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class Solution:
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def hasCycle(self, head: Optional[ListNode]) -> bool:
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cnt = 0
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if head == None: return False
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while cnt < 1e4+10:
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if head.next == None:
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return False
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head = head.next
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cnt += 1
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return True
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