Java实现-合并两个排序链表

将两个排序链表合并为一个新的排序链表

您在真实的面试中是否遇到过这个题？ 

Yes

样例

给出 1->3->8->11->15->null，2->null， 返回 1->2->3->8->11->15->null。

/** * Definition for ListNode. * public class ListNode { *     int val; *     ListNode next; *     ListNode(int val) { *         this.val = val; *         this.next = null; *     } * } */ public class Solution {    /**     * @param ListNode l1 is the head of the linked list     * @param ListNode l2 is the head of the linked list     * @return: ListNode head of linked list     */    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {        // write your code here        if(l1==null)return l2;if(l2==null)return l1;ListNode dummy=new ListNode(-1);ListNode node=dummy;while(l1!=null&&l2!=null){if(l1.val>l2.val){node.next=new ListNode(l2.val);node=node.next;l2=l2.next;}else{node.next=new ListNode(l1.val);node=node.next;l1=l1.next;}}if(l1==null){node.next=l2;}if(l2==null){node.next=l1;}return dummy.next;    }}