牛客 NC33 合并有序链表(合并链表)

    public ListNode mergeTwoLists (ListNode l1, ListNode l2) {
    
    
        ListNode dummyHead = new ListNode(0);
        ListNode node = dummyHead;
        while(l1 != null && l2 != null){
    
    
            if(l1.val < l2.val){
    
    
                node.next = l1;
                l1 = l1.next;
            }else{
    
    
                node.next = l2;
                l2 = l2.next;
            }
            node = node.next;
        }
        if (l1 != null) node.next = l1;
        if (l2 != null) node.next = l2;
        return dummyHead.next;
    }