LeetCode-21 Merge Two Sorted Lists(合并两个有序链表)

LeetCode-21 Merge Two Sorted Lists(合并两个有序链表)

 

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.

 

代码：

public class Solution {    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {ListNode flag = new ListNode(0);ListNode firstflag = flag;//标记第一个节点位置。while (l1 != null && l2 != null) {//★if(l1.val < l2.val){flag.next = l1;l1 = l1.next;}else {flag.next = l2;l2 = l2.next;}flag = flag.next;}flag.next = l1 != null ? l1 : l2; return firstflag.next;    }}

事实上我认为在★的循环体内部能够进行优化。

在该处再加入while循环，判断L2新节点和l1当前节点的大小，如果依旧比l1当前节点大，则l2=l2.next~直到出现比当前节点大的节点，就将L2的上一个节点与l1连接，并l1的下一个节点继续判断...（重复刚刚l2的推进过程）...，这样可以减少连接次数。