考察對連結串列的操作，注意要把原連結串列恢復原樣

class Solution(object):
    def copyRandomList(self, head):
        """
        :type head: RandomListNode
        :rtype: RandomListNode
        """
        if not head:
            return None
        p=head 
        while p:
            newtmp = RandomListNode(p.label)
 

            newtmp.next=p.next
            p.next=newtmp
            p=p.next.next
        
        p=head
        while p:
            if p.random:
                p.next.random = p.random.next
            p=p.next.next 
        newHead=head.next
        p=head
        newLN=newHead
        while newLN.
 
next:
            p.next = newLN.next
            p=p.next
            newLN.next = p.next
            newLN = newLN.next
        p.next=None
        newLN.next = None
        return newHead