[sword finger offer] sword finger offer 35 Replication of complex linked list

subject
Code
Execution time ：48 ms, In all Python3 Defeated in submission 18.68% Users of
Memory consumption ：15.7 MB, In all Python3 Defeated in submission 73.78% Users of
Pass the test case ：18 / 18

class Solution:
    def copyRandomList(self, head: 'Node') -> 'Node':
        if not head: return
        dic = {
    }
        # 3.  Copy each node , And establish  “ Original node  ->  New node ”  Of  Map  mapping 
        cur = head
        while cur:
            dic[cur] = Node(cur.val)
            cur = cur.next
        cur = head
        # 4.  Building new nodes  next  and  random  Point to 
        while cur:
            dic[cur].next = dic.get(cur.next)
            dic[cur].random = dic.get(cur.random)
            cur = cur.next
        # 5.  Return the head node of the new linked list 
        return dic[head]

【 Method 2】
Execution time ：32 ms, In all Python3 Defeated in submission 94.64% Users of
Memory consumption ：15.7 MB, In all Python3 Defeated in submission 73.78% Users of
Pass the test case ：18 / 18

class Solution:
    def copyRandomList(self, head: 'Node') -> 'Node':
        if not head: return
        cur = head
        while cur:
            newNode=Node(cur.val)
            newNode.next=cur.next
            cur.next=newNode
            cur=newNode.next
        cur=head
        while cur:
            if cur.random:
                cur.next.random=cur.random.next
            cur=cur.next.next
        ans=cur=head.next
        pre=head
        while cur.next:
            pre.next=pre.next.next
            cur.next=cur.next.next
            pre=pre.next
            cur=cur.next
        pre.next=None
        return ans