ValidPalindrome.java

import java.util.Scanner;

class Solution 

{
    public boolean isPalindrome(String s) 
    {
        
        int i = 0;
        int j = s.length()-1;
        
        
        
        while(i<j)
        {
            while(i<j && !Character.isLetterOrDigit(s.charAt(i)))
            {
                i++;
            }
            while (i<j && !Character.isLetterOrDigit(s.charAt(j)))
            {
                j--;
            }
            if(i<j && Character.toLowerCase(s.charAt(i++)) != Character.toLowerCase(s.charAt(j--)))
            {
                return false;
            }
            
        }
        return true;
        
    }
    
    public static void main(String args[])
    {
          Scanner scan = new Scanner;
          String str = scan.nextLine();
          if(isPalindrome(str))
          {
              System.out.println("Palindrome");
          }
          else
          {
              System.out.println("Not a Palindrome");
          }
    }
}