lists, that is$,$ two linked list joined into one. In this example, the data structure is

implemented to group two separate lists of numbers, one consists of lists of even

numbers and the other consists of lists of odd numbers.

Node from main list:

Node from secondary list:

Figure $1$: A list of two lists

Two types of linked list are used in the above implementation. The node of the

main list $($highlighted in grey$)$ consists of a content field, a next node field, and a

next list field. The content node holds a value $0$ for an odd list and a value $1$ for

an even list. The node also contains two reference fields. The first is a 'next node'

that links to the first node of a secondary list, and the second is a 'next list' that

links to the next link list.

The node of the secondary list $($non$-$highlighted$)$ consists of a content field and a

next node field. For an even list, the content holds an even number and for an

odd list, the content holds an odd number. The node has a 'next node' field that

link it to the next secondary list node.

In a single linked list implemented in Java, this is the definition of a node:

class Node $\{$

int data;

Node nextNode;

$//$ Constructor to create a new node

$//$ nextNode is by default initialized as null

Node $($int d$)\{$ data $=d$;