The article directories

Java – Bidirectional linked lists of data structures
1. Realization of single linked list
- (1) Define a node type
- (2) Head insertion method
- (3) Tail insertion method
- (4) Insert nodes according to subscripts
- (5) Search keywords
- (6) Delete the first occurrence of the keyword
- (7) Delete all the key words
- (8) Node recovery
- (9) Printed display of linked list
2. Complete code display
Finished!

Java – Bidirectional linked lists of data structures

Move on to Java — singly linked lists of data structures

In the previous study, we mainly understand a lot of Basic Syntax of Java, but in the later Java learning, it is very important to understand the knowledge of basic data structure, the idea of data structure can help us more clearly understand the idea of Solving problems in Java and so on.

Today we are going to start learning how to implement a Java based bidirectional acyclic list without spearhead.

1. Realization of single linked list

(1) Define a node type

We create a ListNode class as the node type, so how do we define member attributes?

From the above structural analysis, we need to define two member variables val – as the stored value of the node, next – to hold the address/reference of the next node, and prev – to hold the address/reference of the previous node

And once defined, their default values are 0, NULL, null, so to assign a value to this node, write a constructor that saves the value first.

Here we provide two constructors, one to implement the node that provides the value, and the other to implement the node that does not provide the value, for our convenience later.

As a bidirectional list, we can traverse from the beginning node to the end node, as well as from the end node to the end node, so we define two nodes — head head node and last tail node

    public ListNode head;
    public ListNode last;
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We then implement the various methods of a single LinkedList in the LinkedList class.

(2) Head insertion method

Take the above structure as an example, this single linked list has no special puppet node to act as the head node, the first node is defined as the head node, so the head interpolation method, we define a node, inserted at the front of the list, as the new head.

Ideas:

There are two cases: