// @Title: 训练计划 IV (训练计划 IV)
// @Author: qisiii
// @Date: 2022-02-20 21:07:47
// @Runtime: 0 ms
// @Memory: 41.3 MB
// @comment: 
// @flag: 
/**
 * 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){
            return l2;
        }
        if(l2==null){
            return l1;
        }
        ListNode temp;
        if(l1.val<l2.val){
            temp=l1;
            l1=l1.next;
        }else{
            temp=l2;
            l2=l2.next;
        }
        temp.next=mergeTwoLists(l1,l2);
        return temp;
    }
}