[leetcode]21.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.

连接两个有序链表，链接后依然有序。

遍历两个链表，依次讲较小节点加入新的链表当中。

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