The following Java code implements a Stack using an ArrayList. Write a method "peek", that returns the String at the top of the Stack without removing the String from the Stack. Write 'peek' using only the methods that currently exist in the Stack class. import java.util.*; public class Stack { private ArrayList elements = new ArrayList<>(); public String pop() { if (elements.isEmpty()) { return null; } String top = elements.get(elements.size() - 1); elements.remove(elements.size() - 1); return top; } public void push (String element) { elements.add(element); } public boolean isEmpty() { } return elements.isEmpty();

The following Java code implements a Stack using an ArrayList. Write a method "peek", that returns the String at the top of the Stack without removing the String from the Stack. Write 'peek' using only the methods that currently exist in the Stack class. import java.util.*; public class Stack { private ArrayList elements = new ArrayList<>(); public String pop() { if (elements.isEmpty()) { return null; } String top = elements.get(elements.size() - 1); elements.remove(elements.size() - 1); return top; } public void push (String element) { elements.add(element); } public boolean isEmpty() { } return elements.isEmpty();

C++ Programming: From Problem Analysis to Program Design

8th Edition

ISBN:9781337102087

Author:D. S. Malik

Publisher:D. S. Malik

Chapter18: Stacks And Queues

Section: Chapter Questions

Problem 16PE: The implementation of a queue in an array, as given in this chapter, uses the variable count to...

See similar textbooks

Similar questions

don't use others answers java 1. Write a generic static method that takes a Stack of any type element as a parameter, pops each element from the stack, and prints it. It should have a type parameter that represents the Stack’s element type.
Implement a simple stack in java using the scenario below. A company wishes to keep track of the order in which it employed staff. Users can enter either "f" to fire, "h" to hire or "e" to end the program. When a member of staff is employed, their employee number is added to the top of a stack when someone has to be made redundant, the last person to join the company is removed from the top of the stack. Hint: Use ArrayList
IN JAVA Implement the method public void display() which displays the entries in a stack starting from the top. If the stack is empty, print “The stack is empty”. Add the method to ArrrayStack2.java. You do not need to modify StackInterface.java.
IN JAVA First, Implement the method public void display() which displays the entries in a stack starting from the top. If the stack is empty, print “The stack is empty”. Add the method to ArrrayStack2.java. You do not need to modify StackInterface.java. Then, Implement a method public int remove(int n) The method removes the n top most entries for a stack . If the stack contains less than n items, the stack becomes empty. The method returns the number of items removed. Add the method to ArrrayStack2.java. You do not need to modify StackInterface.java. Then, Suppose that in the array-based stack, the array doubles in size after multiple push operations. But later on, fewer than half of the array’s locations might actually be used by the stack due to pop operations. Revise the implementation so that its array also can shrink in size as objects are removed from the stack. Accomplishing this task will require two new private methods, as follows: The first new method checks whether we…
The implementation of a queue in an array, as given in this chapter, uses the variable count to determine whether the queue is empty or full. You can also use the variable count to return the number of elements in the queue. On the other hand, class linkedQueueType does not use such a variable to keep track of the number of elements in the queue. Redefine the class linkedQueueType by adding the variable count to keep track of the number of elements in the queue. Modify the definitions of the functions addQueue and deleteQueue as necessary. Add the function queueCount to return the number of elements in the queue. Also, write a program to test various operations of the class you defined.
Please help with the following in Java Write a Java program create a stack with elements pushed 1, 2, 3, 4 and 5, removes the middle element. Note that you may use only push(), pop(), peek() and empty() methods of the stack.
Create an interface called Stack with methods Push (), Pop () and property Length.Create a class that implements this interface. Use an array to implement stack datastructure. language C#
Lab 18: Stack, SentenceReverser Java language Use a stack to reverse the words of a sentence. Keep reading words until you have a word that ends in a period, adding them onto a stack. When you have a word with a period, pop the words off and print them. Stop when there are no more words in the input. For example, you should turn the inputMary had a little lamb. Its fleece was white as snow.intoLamb little a had mary. Snow as white was fleece its.Pay attention to capitalization and the placement of the period.
b. import java.util.ArrayList; public class Main { public static void main (String[]args) { ArrayList snacks = new ArrayList 0; snacks.add ("Grapes"); snacks.add ("Apples"); snacks.add ("Orange"); snacks.add (2, "Carrots"); snacks.remove (0); System.out.println (snacks.get(1)); System.out.println (snacks.get(2)); } }
Write a method of the ArrayBoundedStack class to swap the item at the bottom of the stack with the item at the top of the stack. Do not use any other stack methods in your code. The fields of the ArrayBoundedStack are:
Question3. Using the Stack class implemented in JAVA, write a JAVA code to do the following: a. Create an array of integers containing the following elements: 5, -1, 7,8,9,4,15 b. Create an empty stack (call it nums) and push all the array elements onto the stack. c. Using a temporary stack to reverse the content of the stack nums then print it. d. Display all odd elements from the stack nums.
Write a method called removeBelow in the class StackApplication that accepts two parameters called elem of type int and an ArrayStack of integers st. The method should remove all the elements of the stack that are below elem from the stack. Example: elem: 15 top Stack (before method call): 20 14 18 16 10 top Stack (After method call): 20 18 16 Method heading: public static void removeBelow(int elem, ArrayStack<Integer> st)