Python solution
Does't matter if the length of the list is odd or even, find mid, split, reverse the second list and insert. Pretty straightfowward.\n\n    class Solution(objec
Does't matter if the length of the list is odd or even, find mid, split, reverse the second list and insert. Pretty straightfowward.\n\n    class Solution(object):\n    def reorderList(self, head):\n        if not head or not head.next or not head.next.next: return\n        slow, fast=head, head\n        while fast.next and fast.next.next: slow, fast=slow.next, fast.next.next\n        head1, head2=head, slow.next\n        slow.next, cur, pre=None, head2, None\n        while cur:\n            curnext=cur.next\n            cur.next=pre\n            pre=cur\n            cur=curnext\n        cur1, cur2=head1, pre\n        while cur2:\n            next1, next2=cur1.next, cur2.next\n            cur1.next=cur2\n            cur2.next=next1\n            cur1, cur2=next1, next2
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