Java Program to Count and Show the Repeated Words in a String without using HashMap

Java Program to Count and Show the Repeated Words in a String without using HashMap

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In the previous article, we have discussed about Java Program to Reverse Sequence of Words of a Sentence

In this article we will see how to count and show the repeated words in a string without using Hashmap in Java programming language.

Java Program to Count and Show the Repeated Words in a String without using HashMap

As per the problem statement, it requires to count and show repeated words in the String without Hashmap. So, let’s do it by using array.

For example:

If the string is "abc bca cba abc abc cba"
Then the duplicate strings are-
abc=3
cba=2

Let’s see the program to understand it more clearly.

Method-1: Java Program to Count and Show the Repeated Words in a String without using HashMap (By Using Array) & Static Input Value

Approach:

  • Declare a string variable and initialize it’s value.
  • Convert that string value to lowercase by using toLowerCase() method, which will be easy to compare.
  • Then split the string based on space by using split() method and store the string elements in an String array.
  • Then compare each elements with other elements of string array by using equals() method and keep track on occurrence of values.
  • Then by using an if condition check the elements whose occurrence is greater than 1, those elements are repeated words.

Program:

public class Main 
{    
    public static void main(String[] args) 
    {    
        String str = "abc bca cba abc abc cba";    
        int count;    
            
        //Converting the string into lowercase which will be easy to compare 
        str = str.toLowerCase();
        //splitted string based on space
        String word[] = str.split(" ");    
            
        System.out.println("Duplicate words in a given string : ");     
        for(int i = 0; i < word.length; i++) 
        {   
           // initializing count as 1
            count = 1;  
            //comparing each word with other words till last
            for(int j = i+1; j < word.length; j++) 
            {    
                if(word[i].equals(word[j]))
                {    
                   count++;
                   //it will not print visited word
                   word[j] = "0";    
                }    
            }    
                
            //duplicate word if count is greater than 1    
            if(count > 1 && word[i] != "0")    
                System.out.println(word[i]+"="+count);    
        }    
    }    
}

Output:

Duplicate words in a given string : 
abc=3
cba=2

Method-2: Java Program to Count and Show the Repeated Words in a String without using HashMap (By Using Array) & User Input Value

import java.util.*;

public class Main {    
    public static void main(String[] args) 
    {    
        int count;    
        Scanner sc = new Scanner(System. in );
        System.out.println("Enter a string/sentence");
        String str = sc.nextLine();   
        //Converting the string into lowercase which will be easy to compare 
        str = str.toLowerCase();
        //splitted string based on space
        String word[] = str.split(" ");    
            
        System.out.println("Duplicate words in a given string : ");     
        for(int i = 0; i < word.length; i++) 
        {   
           // initializing count as 1
            count = 1;  
            //comparing each word with other words till last
            for(int j = i+1; j < word.length; j++) 
            {    
                if(word[i].equals(word[j]))
                {    
                   count++;
                   //it will not print visited word
                   word[j] = "0";    
                }    
            }    
                
            //duplicate word if count is greater than 1    
            if(count > 1 && word[i] != "0")    
                System.out.println(word[i]+"="+count);    
        }    
    }    
}

Output:

Enter a string/sentence
I love Java I love BtechGeeks BtechGeeks BtechGeeks
Duplicate words in a given string : 
i=2
love=2
btechgeeks=3

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