LeetCode-合并两个有序链表-简单

将两个升序链表合并为一个新的 升序 链表并返回。新链表是通过拼接给定的两个链表的所有节点组成的。

输入：l1 = [1,2,4], l2 = [1,3,4]
输出：[1,1,2,3,4,4]

输入：l1 = [], l2 = []
输出：[]

输入：l1 = [], l2 = []
输出：[]

两个链表的节点数目范围是 [0, 50]
-100 <= Node.val <= 100
l1 和 l2 均按 非递减顺序 排列

		public ListNode mergeTwoLists(ListNode l1, ListNode l2) {

        if (l1 == null)
            return l2;
        if (l2 == null)
            return l1;
        ListNode merge = new ListNode();
        ListNode result = new ListNode();
        result = merge;
        while (l1 != null && l2 != null) {
            if (l1.val <= l2.val){
                merge.val = l1.val;
                l1 = l1.next;
            }else{
                merge.val = l2.val;
                l2 = l2.next;
            }
            //System.out.println(merge.val);
            if (l1 != null && l2 != null){
                ListNode p = new ListNode(0, null);
                merge.next = p;
                merge = merge.next;
            }
        }
        if (l1 == null) {
            merge.next = l2;
        }else {
            merge.next = l1;
        }

        return result;
    }