题目链接：https://leetcode-cn.com/problems/fu-za-lian-biao-de-fu-zhi-lcof/
难度：中等

描述：
请实现 copyRandomList 函数，复制一个复杂链表。在复杂链表中，每个节点除了有一个 next 指针指向下一个节点，还有一个 random 指针指向链表中的任意节点或者 null。

题解

  1. """
  2. # Definition for a Node.
  3. class Node:
  4.     def __init__(self, x: int, next: 'Node' = None, random: 'Node' = None):
  5.         self.val = int(x)
  6.         self.next = next
  7.         self.random = random
  8. """
  9. class Solution:
  10.     def copyRandomList(self, head: 'Node') -> 'Node':
  11.         if head is None:
  12.             return None
  14.         temp = head
  15.         while temp is not None:
  16.             new_node = Node(temp.val, temp.next)
  17.             temp.next = new_node
  18.             temp = new_node.next
  20.         temp = head
  21.         while temp is not None:
  22.             if temp.random is not None:
  23.                 temp.next.random = temp.random.next
  24.             temp = temp.next.next
  26.         temp = head
  27.         ret = head.next
  28.         cur = ret
  29.         while cur.next:
  30.             temp.next = cur.next
  31.             temp = temp.next
  32.             cur.next = temp.next
  33.             cur = cur.next
  34.         temp.next = None
  35.         return ret