Implementation of tri-tree in Java

Java implementation of tri-tree

What is a trie tree?

Untitled Diagram.png

A trie tree is a kind of ordered tree, and it is an algorithm in which characters are stored in each node and a search can be performed by tracing the nodes.

Write in Java

Create a class that represents a node

public class Node {
	private int id;
	private String str;
	private ArrayList<Node> child = new ArrayList<>();
	public int getId() {
	public String getStr() {
		return this.str;
	public ArrayList<Node> getChild(){
		return this.child;
	public void setId(int id) { = id;
	public void setStr(String str) {
		this.str = str;
	public void setChild(Node node) {

The id identifies the node and does not have to be separate str is the character to store in the node child is supposed to store the child of the node

Trees can be built as follows

public class Main {
	private static ArrayList<Node> nodeList = new ArrayList<>();
	private static int id = 1;
	public static void insert(Node parent, String word, int charIndex) {
		String w = String.valueOf(word.charAt(charIndex));
		if(charIndex == word.length()-1) { //For the last character
			for(Node n:parent.getChild()) { //If the last node is an existing node
				if(n.getStr() != null&&n.getStr().equals(w)) {
			Node node = new Node();
			id += 1;
		for(Node n:parent.getChild()) { //If the child contains the current ward
			if(n.getStr() != null&&n.getStr().equals(w)) {
		Node node = new Node();
		id += 1;
		if(charIndex < word.length()-1) { //Recursive processing
		     insert(node, word, charIndex+1);

I'm sorry if I made a mistake because it was rewritten for the article that I wrote when I was making another algorithm with a little ingenuity in the trie tree (_ _)


This time, I had a chance to use a tri-tree, so I tried to implement it in java, but it took a long time to understand because it uses recursive processing. After all, I am not good at recursive processing, so I want to actively use it to eliminate my weakness ...

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