LinkedList:合并2个有序单链表

public Node mergeTwoLists(Node l1, Node l2) {
        if (l1==null ||l2==null) {
            return l1!=null?l1:l2;
        }
        Node head = null;
        if (l1.value<l2.value) {
            head = l1;
            l1 = l1.next;
        } else {
            head = l2;
            l2 = l2.next;
        }
        Node last = head;
        while (l1!=null&&l2!=null) {
            if (l1.value<l2.value) {
                last.next = l1;
                l1 = l1.next;
            } else {
                last.next = l2;
                l2 = l2.next;
            }
            last = last.next;
        }
        last.next = l1!=null?l1:l2;
        
        return head;
    }