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28 lines
422 B
Python
28 lines
422 B
Python
#!/usr/bin/env python3
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# -*- coding: utf-8 -*-
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# author: bt3gl
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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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def detectCycle(self, head):
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seen = set()
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node = head
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while node is not None:
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if node in seen:
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return node
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else:
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seen.add(node)
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node = node.next
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return None
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