public class Solution { /** * * @param l1 ListNode类 * @param l2 ListNode类 * @return ListNode类 */ public ListNode mergeTwoLists (ListNode l1, ListNode l2) { // write code here if(l1==null){return l2;} if(l2 ==null){return l1;} if(l1.val<l2.val){ l1.next = mergeTwoLists(l1.next,l2); return l1; }els...