How can I print the palindrome words in a sentence? If I input "Madam Arora teaches math", it should print "Madam Arora"

class Palindrome { 
      
    // Function to check if a word is 
    // palindrome 
    static boolean checkPalin(String word) 
    { 
        int n = word.length(); 
        word = word.toLowerCase(); 
        for (int i=0; i<n; i++,n--) 
           if (word.charAt(i) != word.charAt(n - 1)) 
              return false;        
        return true; 
    } 
      
    // Function to count palindrome words 
    static int countPalin(String str) 
    {         
        // to check last word for palindrome 
        str = str + " "; 
          
        // to store each word 
        String word = ""; 
        int count = 0; 
        for (int i = 0; i < str.length(); i++) 
        { 
            char ch = str.charAt(i); 
              
            // extracting each word 
            if (ch != ' ') 
                word = word + ch; 
            else { 
                if (checkPalin(word)) 
                    count++; 
                word = ""; 
            } 
        } 
          
        return count; 
    } 
      
    // Driver code 
    public static void main(String args[]) 
    { 
        System.out.println(countPalin("Madam "
                  + "Arora teaches malayalam")); 
                    
        System.out.println(countPalin("Nitin "
                        + "speaks malayalam")); 
    }
}

I only know how to count the number. How can I run through a loop and check every word if it is a palindrome? Can you help me with a method that checks a word and a method that checks a sentence if there are palindrome words? I must use Stacks and Queues. I have done the push, add, remove, dequeue, but I can't check if the input is a sentence.

// C# program to count number of 
// palindrome words in a sentence 
using System; 
class Palindrome 
{ 
// Function to check if a word is 
// palindrome 
public static bool checkPalin(string word) 
{ 
int n = word.Length; 
word = word.ToLower(); 
for (int i = 0; i < n; i++,n--) 
{ 
if (word[i] != word[n - 1]) 
{ 
return false; 
} 
} 
return true; 
} 
// Function to count palindrome words 
public static int countPalin(string str) 
{ 
// to check last word for palindrome 
str = str + " "; 
// to store each word 
string word = ""; 
string Print_Result = "";
int count = 0; 
for (int i = 0; i < str.Length; i++) 
{ 
char ch = str[i]; 
// extracting each word 
if (ch != ' ') 
{ 
word = word + ch; 
} 
else
{ 
if (checkPalin(word)) 
{ 
if (Print_Result == "")
{
Print_Result =  word;
}else
{
Print_Result = Print_Result + word;
} 
} 
word = ""; 
} 
} 
return Print_Result; 
} 
// Driver code 
public static void Main(string[] args) 
{ 
Console.WriteLine(countPalin("Madam " + 
"Arora teaches math")); 
} 
} 

You need to change only this part

if (checkPalin(word)) 
{ 
OutPut =  OutPut + word;
}

after for loop return OutPut.

You could implement a method to return a list of palindrome words after splitting the input string with String.split.

It is convenient to use Java 8 Stream API for such tasks (filter and collect):

import java.util.*;
import java.util.stream.*;

class Palindrome {
// ...

    public static List<String> findPalindromes(String str) {
        if (null == str || str.isEmpty()) {
            return Collections.emptyList();
        }
        return Arrays.stream(str.split("\\s+")) // split into "words" separated with whitespaces
                     .filter(Palindrome::checkPalin) // keep the palindrome words
                     .collect(Collectors.toList());  // get the list from stream
    }

    // then countPalin() may be refactored as
    public static countPalin(String str) {
        return findPalindromes(str).size();
    }
}

Test

public static void main(String... args) {
    String[] data = { null, "", "None",
                "Madam Arora teaches malayalam",
                "Nitin speaks malayalam"
    };

    for (String str : data) {
        List<String> palindromes = findPalindromes(str);
        if (palindromes.isEmpty()) {
            System.out.printf("No palindromes found in \"%s\"%n", str);
        } else {
            System.out.printf("\"%s\" palindromes found in \"%s\"%n", palindromes, str);
        }
    }
}

Output:

No palindromes found in "null"
No palindromes found in ""
No palindromes found in "None"
"[Madam, Arora, malayalam]" palindromes found in "Madam Arora teaches malayalam"
"[Nitin, malayalam]" palindromes found in "Nitin speaks malayalam"