import java.util.Scanner;

/*

Welcome to Day 18! Review this queues and stacks video and the

Java documentation for implementing stacks and queues

(https://www.youtube.com/watch?v=fOHLom4hZME&feature=youtu.be), or

just jump right into the problem.

A palindrome is a "word, phrase, number, or other sequence of

characters which reads the same backwards and forwards."

Can you determine if a given string, s, is a palindrome?

To solve this challenge, we must first take each character in

s, enqueue it in a queue, and also push it onto a stack.

Once that's done, we must dequeue the first character from

the queue and pop the top character off the stack, then

compare the two characters to see if they are the same;

as long as the characters match, we continue dequeueing,

popping, and comparing each character until our containers

are empty (a non-match means s isn't a palindrome).

Write the following four functions/methods in class Palindrome:

void pushCharacter(char ch): Pushes a character onto a stack.

void enqueueCharacter(char ch): Enqueues a character in a queue.

char popCharacter(): Pops and returns the top character.

char dequeueCharacter(): Dequeues and returns the first character.

Code handling Input/Output and determining if s is palindrome is

provided in the editor.

Input Format

A single line containing string s.

Note: s will always be lowercase.

Output Format

If s is a palindrome, print "The word, s, is a palindrome."

Otherwise, print "The word, s, is not a palindrome." without quotes

Sample Input

racecar

Sample Output

The word, racecar, is a palindrome.

*/

public class Solution {

/* Start the program here */

public static void main(String[] args) {

/* Create an instance of the Scanner class to read standard input */

Scanner stdIn = new Scanner(System.in);

/*

/* Read the string to test as a palindrome */

String inputString = stdIn.nextLine();

/* Create an instance of the Palindrome class */

Palindrome palindrome = new Palindrome();

/* Convert the input string to an array of characters */

char arrayString[] = inputString.toCharArray();

/* Push all the characters of the string to a stack */

for (char nextChar : arrayString) {

/* Push the next character onto the stack */

palindrome.pushCharacter(nextChar);

}

/* Add all the characters to the queue */

for (char nextChar : arrayString) {

palindrome.enqueueCharacter(nextChar);

}

/* Assume isPalindrome is true */

boolean isPalindrome = true;

/* Compare the top of the stack, with the front of the queue

* to see if it is a palindrome

*/

for (int i = 0; i < inputString.length(); i++) {

if (palindrome.popCharacter() != palindrome.dequeueCharacter()) {

/* At least one character doesn't match; so not a palidrome */

isPalindrome = false;

/* Stop the loop */

break;

}

}

/* Print out if the string is a palindrome or not */

if (isPalindrome) {

System.out.println("The word, " + inputString + ", is a palindrome.");

} else {

System.out.println("The word, " + inputString + ", is not a palindrome.");

}

}

}