leetcode 61. Rotate List

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Given a list, rotate the list to the right by k places, where k is non-negative.

Example:

Given 1->2->3->4->5->NULL and k = 2,

return 4->5->1->2->3->NULL.

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# Definition for singly-linked list.
# class ListNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.next = None
class ListNode2(ListNode):
    def __init__(self,x):
        self.val = x
        self.next = None
    
    def append(self, dataOrNode):
        item = None
        if isinstance(dataOrNode, ListNode):
            item = dataOrNode
        else:
            item = ListNode(dataOrNode)

        if not self:
            self = item

        else:
            node = self
            while node.next:
                node = node.next
            node.next = item

class Solution(object):
    def rotateRight(self, head, k):
        """
        :type head: ListNode
        :type k: int
        :rtype: ListNode
        """
        res = []
        root = head
        if head == None:return None
        while root:
            res.append(root.val)
            root = root.next
        k = k%len(res)
        if k == 0:return head
        res = res[len(res)-1-k::-1] + res[:len(res)-1-k:-1]
        res = res[::-1]
        p = ListNode2(res[0])
        for i in res[1:]:
            p.append(i)
        return p