[LeetCode] Flatten a Multilevel Doubly Linked List 壓平一個多層的雙向鏈表
阿新 • • 發佈：2018-09-21
structure children data more flatten nodes pointer next input
You are given a doubly linked list which in addition to the next and previous pointers, it could have a child pointer, which may or may not point to a separate doubly linked list. These child lists may have one or more children of their own, and so on, to produce a multilevel data structure, as shown in the example below.
Flatten the list so that all the nodes appear in a single-level, doubly linked list. You are given the head of the first level of the list.
Example:
Input:
1---2---3---4---5---6--NULL
|
7---8---9---10--NULL
|
11--12--NULL
Output:
1-2-3-7-8-11-12-9-10-4-5-6-NULL
Explanation for the above example:
Given the following multilevel doubly linked list:
We should return the following flattened doubly linked list:
s
[LeetCode] Flatten a Multilevel Doubly Linked List 壓平一個多層的雙向鏈表