Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.
题目标签:Linked List
题目给了我们两个lists,让我们有序的合并两个 lists。
这题利用递归可以从list 的最后开始向前链接nodes,代码很简洁,清楚。
Java Solution:
Runtime beats 74.35%
完成日期: 06/09/2017
关键词:singly-linked list
关键点:利用递归从最后开始链接nodes
1 /** 2 * Definition for singly-linked list. 3 * public class ListNode { 4 * int val; 5 * ListNode next; 6 * ListNode(int x) { val = x; } 7 * } 8 */ 9 class Solution 10 { 11 public ListNode mergeTwoLists(ListNode l1, ListNode l2) 12 { 13 if(l1 == null) 14 return l2; 15 if(l2 == null) 16 return l1; 17 18 if(l1.val < l2.val) 19 { 20 l1.next = mergeTwoLists(l1.next, l2); 21 return l1; 22 } 23 else 24 { 25 l2.next = mergeTwoLists(l1, l2.next); 26 return l2; 27 } 28 } 29 30 }
参考资料:
https://discuss.leetcode.com/topic/45002/java-1-ms-4-lines-codes-using-recursion
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