Question

Using a queue and a stack, implement a method that tests whether a sequence of numbers...

Using a queue and a stack, implement a method that tests whether a sequence of numbers is a palindrome, that is, equal to the sequence in reverse. For example, [1,2,3,2,1] is a palindrome, but [1,2,2,3,1] is not.

Complete the following file:

QueueStackUtil.java

import java.util.LinkedList;
import java.util.Queue;
import java.util.Stack;

public class QueueStackUtil
{
public static boolean isPalindrome(int[] values)
{
Queue<Integer> queue = new LinkedList<Integer>();
Stack<Integer> stack = new Stack<Integer>();
for (int s : values)
{
// insert s into the queue and stack
}
while (queue.size() > 0)
{
// remove an element from the queue

// remove an element from the stack

// compare the removed elements

}
return ...;
}
}

Homework Answers

Answer #1
QueueStackUtil.java

import java.util.LinkedList;
import java.util.Queue;
import java.util.Stack;

public class QueueStackUtil {
    public static boolean isPalindrome(int[] values) {
        Queue < Integer > queue = new LinkedList < Integer > ();
        Stack < Integer > stack = new Stack < Integer > ();
        for (int s: values) {
            stack.push(s);
                        queue.add(s);
        }
                int x, y;
        while (queue.size() > 0) {
            // remove an element from the queue
                        x = queue.remove();

            // remove an element from the stack
                        y = stack.pop();
                        
            // compare the removed elements
                        if(x != y)
                                break;

        }
                boolean isP;
                
                if(x != y)
                        isP = false;
                else
                        isP = true
        return isP;
    }
}

if you have any doubt, feel free to ask in the comments.

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
ex3 Write a method public static boolean isPalindrome(String input) that uses one or more stacks to...
ex3 Write a method public static boolean isPalindrome(String input) that uses one or more stacks to determine if a given string is a palindrome. [A palindrome is a string that reads the same forwards and backwards, for example ‘racecar’, ‘civic’]. Make sure that your method works correctly for special cases, if any. What is the big-O complexity of your method in terms of the list size n. Supplementary Exercise for Programming (Coding) [Stacks] Download and unpack (unzip) the file Stacks.rar....
Stack Queue Program Implement a Stack class using the List Class you developed earlier. Test your...
Stack Queue Program Implement a Stack class using the List Class you developed earlier. Test your Stack class by determining if the following strings have matching open and closing ( ) and/or [ ] and/or { }. To test matches, push open (, [, { onto the stack. Input a close char, pop off the stack and see if input matches symbol form stack.   Use the following data to test your code:                               ( )                               [ ] ( )...
TestQueue.java Design a class named Queue for storing integers. Like a stack, a queue holds elements....
TestQueue.java Design a class named Queue for storing integers. Like a stack, a queue holds elements. But in a queue, the elements are retrieved in a first-in first-out fashion. The class contains: An int[] data field named elements that stores the int values in the queue. A data field named size that stores the number of elements in the queue. A constructor that creates a Queue object with default capacity 8. The method enqueue(int v) that adds v into the...
10.6 LAB: Implement a stack using an array Given main() complete the Stack class by writing...
10.6 LAB: Implement a stack using an array Given main() complete the Stack class by writing the methods push() and pop(). The stack uses an array of size 5 to store elements. The command Push followed by a positive number pushes the number onto the stack. The command Pop pops the top element from the stack. Entering -1 exits the program. Ex. If the input is Push 1 Push 2 Push 3 Push 4 Push 5 Pop -1 the output...
import java.util.Stack; import java.util.Scanner; class Main { public static void main(String[] args)    {       ...
import java.util.Stack; import java.util.Scanner; class Main { public static void main(String[] args)    {        Stack<Integer> new_stack = new Stack<>();/* Start with the empty stack */        Scanner scan = new Scanner(System.in);        int num;        for (int i=0; i<10; i++){//Read values            num = scan.nextInt();            new_stack.push(num);        }        int new_k = scan.nextInt(); System.out.println(""+smallerK(new_stack, new_k));    }     public static int smallerK(Stack s, int k) {       ...
Java Please [(1)] A palindrome is a string that reads the same forwards as backwards. Using...
Java Please [(1)] A palindrome is a string that reads the same forwards as backwards. Using only a fixed number of stacks and queues, the stack and queue ADT functions, and a fixed number of int and char variables, write an algorithm to determine if a string is a palindrome. Assume that the string is read from standard input one character at a time. The algorithm should output true or false as appropriate [(2)] Let Q be a non-empty queue,...
Given main() complete the Stack class by writing the methods push() and pop(). The stack uses...
Given main() complete the Stack class by writing the methods push() and pop(). The stack uses an array of size 5 to store elements. The command Push followed by a positive number pushes the number onto the stack. The command Pop pops the top element from the stack. Entering -1 exits the program. Ex. If the input is Push 1 Push 2 Push 3 Push 4 Push 5 Pop -1 the output is Stack contents (top to bottom): 1 Stack...
Consider a generic Stack class implemented using linked list with the following methods: public boolean isEmpty(),...
Consider a generic Stack class implemented using linked list with the following methods: public boolean isEmpty(), which returns true if and only if the stack is empty; public T pop() throws StackUnderflowException, which removes and returns the top element of the stack (if the stack is empty, it throws StackUnderflowException); public T peek() throws StackUnderflowException, which returns the top element of the stack (but does not remove it; it throws exception if stack is empty); public void push(T element), which...
The language is Java. Using a singly-linked list, implement the four queue methods enqueue(), dequeue(), peek(),...
The language is Java. Using a singly-linked list, implement the four queue methods enqueue(), dequeue(), peek(), and isEmpty(). For this assignment, enqueue() will be implemented in an unusual manner. That is, in the version of enqueue() we will use, if the element being processed is already in the queue then the element will not be enqueued and the equivalent element already in the queue will be placed at the end of the queue. Additionally, you must implement a circular queue....
Write in Java (Not Javascript) Provide an implementation of priority queue using double-ended doubly linked lists....
Write in Java (Not Javascript) Provide an implementation of priority queue using double-ended doubly linked lists. Recall that double-ended means keeping first and last references and doubly linked feature allows us to go backwards, using a prev reference at each Link. Also, note that the greater the number, the lower the priority. For instance, 2 is of higher priority compared to 5. Specifically, write a class LinkedListPriorityQ which implements the priority queue methods: boolean isEmpty() void enqueue(int item) int dequeue()...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT