输入两个递增排序的链表,合并这两个链表并使新链表中的节点仍然是递增排序的。
示例1:
输入:1->2->4, 1->3->4 输出:1->1->2->3->4->4
/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * } */ class Solution { public ListNode mergeTwoLists(ListNode l1, ListNode l2) { if(l1==null||l2==null) return l1==null?l2:l1; ListNode dum = new ListNode(0);//初始化一个空节点,初始赋值为0,指针指向为dum ListNode cur=dum; while(l1!=null&&l2!=null) { if(l1.val<l2.val) { cur.next=l1; l1=l1.next; } else { cur.next=l2; l2=l2.next; } cur=cur.next; } cur.next=l1!=null?l1:l2; return dum.next; } }