51 lines
691 B
Python
51 lines
691 B
Python
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class LinkedListNode:
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def __init__(self, val):
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self.val = val
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self.next = None
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def reverse(head):
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curr = head
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prev = None
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next = None
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while curr:
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# save next node
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next = curr.next
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# reverse curr's pointer
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curr.next = prev
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# advance curr and prev
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prev = curr
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curr = next
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head = prev
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return head
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head = LinkedListNode(1)
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head.next = LinkedListNode(2)
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head.next.next = LinkedListNode(3)
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# print list
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node = head
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while node:
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print(node.val)
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node = node.next
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head = reverse(head)
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# print list
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node = head
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while node:
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print(node.val)
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node = node.next
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