Thread: Data Structure

What have you tried? Dumping homework questions is not a great way to get advice as no one is going to do these for you. Rather, attempting the problems and showing what you've done, describing where you are stuck, what errors you receive is a much better alternative. Suggested reading: How To Ask Questions The Smart Way

i dono how to start or what to do for first step?
can u answer this Q?

No, I won't do your homework for you (and according the forum policy, anyone that does may have their posts edited to remove solutions). Break the problem down to the requirements and look through the tutorials: The Java™ Tutorials .

public static void main(String[] args)
{	
String input = "";
String str = "";
Scanner scan = new Scanner(System.in);
System.out.print("Enter a string: ");
while(true)
{
 
str = scan.nextLine();
if(str.length() == 0)
break;
if(str.length() > 1)
{
System.out.println("Only one character");
str= scan.nextLine();
}
 
input+= str;
}
 
Palindrome result = new Palindrome(input);
if(result.isPalindrome())
System.out.println("This is a Palindrome string");
else
System.out.println("This is not a Palindrome string"); 
}

* so is that right code?

/* Recursive Function*/
gcd(int n,int m)
	{ if(m<=n && n%m == 0)
	   return m;
	  if(n < m)
	   return gcd(m,n);
	  else
	   return gcd(m,n%m);
	 }

*this for the recursive ? its right too or not ?

import java.util.*;
public class CheckPalindrome{
public static void main(String[]args){
Scanner input=new Scanner(System.in);
System.out.print("Enter String: ");
String st=input.next();
String str[]=st.split("");
String reversedSt="";
for(int i=str.length-1;i>=0;i--){
reversedSt+=str[i];
}
if(st.equalsIgnoreCase(reversedSt)){
System.out.println("String is palindrome");
}
else{
System.out.println("String is not palindrome");
}
}
}

how can i write this code using stacks "java" ?