Java Program to Implement Hash Trie

Code:

import java.io.*;
import java.util.*;

class HashTrie
{
    private HashMap root;

    /** Constructor **/
    public HashTrie() 
    {
       root = new HashMap();
    }
    /** Parameterised Constructor **/
    public HashTrie(String[] arr) 
    {
        root = new HashMap();
        for (String s: arr)
            add(s);
    }

    /** Function to add a string to hash trie **/
    public void add(String str) 
    {
        HashMap node = root;
        for (int i = 0; i < str.length(); i++)
        {
            if (node.containsKey(str.charAt(i)))
                node = node.get(str.charAt(i));
            else 
            {
                node.put(str.charAt(i), new HashMap());
                node = node.get(str.charAt(i));
            }
        }
        /** end of string **/
        node.put('\0', new HashMap(0)); 
    }

    /** Function to check if hash trie contains a given word **/
    public boolean contains(String str) 
    {
        HashMap currentNode = root;
        for (int i = 0; i < str.length(); i++)
        {
            if (currentNode.containsKey(str.charAt(i)))
                currentNode = currentNode.get(str.charAt(i));
            else 
                return false;
        }        
        return currentNode.containsKey('\0') ? true : false;            
    }
}

/** Class HashTrieTest **/
public class HashTrieTest
{
    public static void main(String[] args) throws IOException
    {    
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        /** Accept words **/        
        System.out.println("Trie Test\n");
        System.out.println ("Enter words to be entered into trie");
        String input = br.readLine();
        String[] s = input.split(" ");
        /** Create Trie with accepted words **/
        HashTrie t = new HashTrie(s);
        /** Trie Test **/
        char ch = 'n';
        do
        { 
            System.out.println("\nEnter word to search ");
            String key = br.readLine();
            System.out.println("Search status : "+ t.contains(key));

            System.out.println("\nDo you want to continue (Type y or n) \n");
            ch = br.readLine().charAt(0);                        
        } while (ch == 'Y'|| ch == 'y');         
    }
}


Output:

Trie Test

Enter words to be entered into trie
trie tree test branch leaf root fruit key lock hash

Enter word to search
trie
Search status : true

Do you want to continue (Type y or n)

y

Enter word to search
tree
Search status : true

Do you want to continue (Type y or n)

y

Enter word to search
trench
Search status : false

Do you want to continue (Type y or n)

y

Enter word to search
triee
Search status : false

Do you want to continue (Type y or n)

y

Enter word to search
trei
Search status : false

Do you want to continue (Type y or n)

y

Enter word to search
branch
Search status : true

Do you want to continue (Type y or n)

n



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