@@ -0,0 +1,889 @@
+/**%0A * Definition for singly-linked list.%0A * public class ListNode %7B%0A *     int val;%0A *     ListNode next;%0A *     ListNode(int x) %7B val = x; %7D%0A * %7D%0A */%0Apublic class Solution %7B%0A    public ListNode mergeTwoLists(ListNode l1, ListNode l2) %7B%0A        // the first three lines can speed up the algorithm%0A        if(l1 == null && l2 == null) return null;%0A        if(l1 == null) return l2;%0A        if(l2 == null) return l1;%0A        %0A        ListNode dummy = new ListNode(0);%0A        ListNode current = dummy;%0A        while(l1 != null && l2 != null) %7B%0A        %09if(l1.val %3C l2.val) %7B%0A        %09%09current.next = l1;%0A        %09%09l1 = l1.next;%0A        %09%7D else %7B%0A        %09%09current.next = l2;%0A        %09%09l2 = l2.next;%0A        %09%7D%0A        %09current = current.next;%0A        %7D%0A        if(l1 != null)      current.next = l1;%0A        else if(l2 != null) current.next = l2;%0A        return dummy.next;        %0A    %7D%0A%7D%0A

Create 021.java