LeetCode 88 Merge Two Sorted Lists

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.

分析：

开一个dummy头，之后两两比较接在后面就可以了。

/** * Definition for singly-linked list. * public class ListNode { *     int val; *     ListNode next; *     ListNode(int x) { *         val = x; *         next = null; *     } * } */public class Solution {    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {        ListNode dummy = new ListNode(0);        ListNode p = dummy;        while(l1 != null && l2 != null){            if(l1.val >= l2.val){                p.next = l2;                p = p.next;                l2 = l2.next;            }else{                p.next = l1;                p = p.next;                l1 = l1.next;            }        }        if(l1==null)            p.next=l2;        else            p.next=l1;                return dummy.next;    }}