LeetCode Linked List Easy 21. Merge Two Sorted Lists

 Description

Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.

Example:

Input: 1->2->4, 1->3->4
Output: 1->1->2->3->4->4

 问题描述，将两个排序的链表归并

代码：

public ListNode MergeTwoLists(ListNode l1, ListNode l2) {
        ListNode ln1 = l1;
        ListNode ln2 = l2;
        ListNode res =new ListNode(0);
        ListNode temp = res;
        while(ln1 != null && ln2 != null){
            if(ln1.val < ln2.val){
                temp.next = ln1;
                ln1 =ln1.next;
                temp = temp.next;
            }else{
                temp.next = ln2;
                ln2 =ln2.next;
                temp = temp.next;
            }
        }
        while(ln1 != null){
                temp.next = ln1;
                ln1 =ln1.next;
                temp = temp.next;            
        }
        while(ln2 != null){
                temp.next = ln2;
                ln2 =ln2.next;            
                temp = temp.next;
        }
        return res.next;