public data1 findLink1(int index1)
        {
            data1 return1 = first_address1;

            for (int i = 0; i < index1; i++)
            {
                return1 = return1.get_nextaddress1();
            }

            return(return1);
        }
        public void showingLinkedlist1()
        {
            data1 address01 = first_address1;

            int index2 = 0;

            while (address01 != null)
            {
                Console.WriteLine("data" + index2 + " : " + address01.get_data2());
                address01 = address01.get_nextaddress1();
                index2++;
            }
        }
        public void deleteLinkedlist1(int index1)
        {
            data1 list1 = findLink1(index1);

            if (index1 == 0)
            {
                list1 = current_address1.get_nextaddress1();
                list1.set_prevaddress1(null);
                first_address1 = list1;
            }

            else
            {
                list1.get_nextaddress1().set_prevaddress1(list1.get_prevtaddress());
                list1.get_prevtaddress().set_nextaddress1(list1.get_nextaddress1());
            }

            datasize1--;
        }
        public void addLinkedlist1(int data1)
        {
            if (current_address1 == null)
            {
                current_address1 = new data1();
                first_address1   = current_address1;
                current_address1.set_data2(data1);
            }

            else
            {
                current_address1.set_nextaddress1();
                moveData1        = current_address1;
                current_address1 = current_address1.get_nextaddress1();
                current_address1.set_prevaddress1(moveData1);
                current_address1.set_data2(data1);
            }

            datasize1++;
        }
 public void set_nextaddress1()
 {
     next_address1 = new data1();
 }
 public void set_nextaddress1(data1 setaddress1)
 {
     next_address1 = new data1();
     next_address1 = setaddress1;
 }
 public void set_prevaddress1(data1 setaddress1)
 {
     prev_address1 = new data1();
     prev_address1 = setaddress1;
 }
        public void replaceLinkedlist1(int index1, int data1)
        {
            data1 list1 = findLink1(index1);

            list1.set_data2(data1);
        }