I am trying to figure out stacks and queues and was trying to get this Palindrome program working so I could then play with it and use the Java visualizer site but for some reason the program isn't working correctly. It always states that the input is a palindrome no matter what the user input is.
The book that I got the code from is a little old so I changed a couple small things that I thought needed updating like adding scanner. I wanna use one with a custom array based stack and queue class rather than the java.util.Stack and Queue interface, just for understanding stacks and queues better hopefully.
import java.util.Scanner;
import javax.imageio.IIOException;
public class PalTest {
public static void main(String[]args) throws IIOException
{
Scanner scan = new Scanner(System.in);
PalindromeTesting x = new PalindromeTesting();
I'm in the process of writing a program that determines if a number is a Palindrome or not. I'm not allowed to use strings and am required to use the getSize method shown below. I believe my issue that I'm having is that the "num" is not being called in the getSize method, and therefore not running the while loop, or at least that is what I believe is the issue.
import javax.swing.*; public class getSize{ public static void main( String[] args ) { int num; num = Integer.parseInt (JOptionPane.showInputDialog ( "Please input a number" ));
I am trying to create a program that reads a sentence, such as: "abba is running to the radar" scans this sentence, and then prints out all the palindromes. I am running into issues with my arrays and for statements. Here is my code:
static String palindrome, backwardsLower, palindromeLower, palindromeClean, backwards2, backwards = ""; static String[] words; static int counter; public static void main(String[] args) { palindrome = JOptionPane.showInputDialog("Please enter a phrase. " +
[Code] ...
I am aware that there is a few "useless" variables in there at the moment, I will clean them up (as well as some useless statements, I see those too). The issue comes at about line 17. The variable backwards REMOVES all the spaces from the array, so when it comes time to compare the strings, it is comparing individual words to the ENTIRE string, thus no words will ever be a palindrome.
I want to find the prime palindrome numbers less that a given number by my program. Here is my code, I am trying to find the method to solve the errors when I compile it. It said variable a might not have been initialized in line 41,62,86.
import java.util.Scanner; public class Lab5{ public static void main (String[] args){ System.out.println("Please input a number"); Scanner Input=new Scanner(System.in); int num = Input.nextInt();
I tried to write a program to implement a stack but it has a bug I am unable to solve.The bug is that whenever I choose an operation to perform, eg push, After performing the operation, the loop is executed once again and Invalid choice message appears, i.e. the default case. And then the loop again executes to choose further option. Here is my code
class Stack { private char[] stck; private int len; private int top;
I was doing some exercises of a java tutorial website, and realized when I ran the code that they had , my program just kept running with no result, why is this? It just hangs.
package mystack; public class MyStack { private int maxSize; private int[] stackArray; private int top; public MyStack(int s)
I want to create java program in which i want to inherit stack and queue from a linked list class and also make infix to postfix inherit from stack and periority queue from queue class.Ho can i make this program.
Complete the body of the following method. Use a CharQueue to store the input line as it is being read. The parameter is an EasyReader from Appendix B of the text. Use the method in.charInput( ) to read and return the next character of the EasyReader, and use in.isEOLN( ) to determine whether the next input character is the end-of-line.
public static int counter(EasyReader in) // Precondition: There is a line of input waiting to be read from in. // Postcondition: A line of input has been read from in, up to but not // including the newline character. The return value of the method // is the number of times that the LAST character of the line appeared // somewhere in this line.
[EXAMPLE Input: ABBXDXXZX - The value returned by counter would be 4 for this input since there are 4 X's in the input line.]
***When I look at this I understand that I'm being asked to finish the method, that I have 1 input, which is an "EasyReader" object called in and that I use a CharQueue object along with the method isEOLN( ) to grab characters from in while looking for an end of line and then sticking the values in the queue and then I can go through the queue and figure out the number of times that last character shows up in the queue. I just am at a loss on the "how".
Suppose that a certain airport has one runway, that each airplane takes LandingTime minutes to land and TakeOffTime minutes to take off, and that on the average, TakeOffTime planes take off and LandingTime planes land each hour.
Assume that the planes arrive at random instants of time. (Delays make the assumption to randomness quite reasonable.) There are 2 types of queues: a queue of airplanes waiting to land and a queue of airplanes waiting go take off. Because it is more expensive to keep a plane airborne than to have one waiting on the ground, we assume that the airplanes in the landing queue have priority over those in the take off queue.
Write a program to simulate this airport's operation. You might assume a simulated clock that advances in one-minute intervals. For each minute, generate two random numbers: If the first in less than LandingTime /60, a "landing arrival" has occurred and is added to the landing queue, and if the second is less than TakeOffTime /60, a "takeoff arrival" has occurred and is added to the takeoff queue. Next, check whether the runway is free. If it is, first check whether the landing queue is nonempty, and if so, allow the first plane to land; otherwise, consider the takeoff queue. Have the program calculate the average queue length and the average time that an airplane spends in a queue. You might also investigate the effect of varying arrival and departure rates to simulate the prime and slack times of day, or what happens if the amount of time to land or takeoff is increased or decreased.
My Queue Interface: [URL] .... My Queue Implementation: [URL] .... My Demo (Main Method) Program: [URL] ....
Right now, I'm struggling with the demo program. I wrote some pseudocode in which I tried to match what the instructions were asking:
Firstly, exactly how many minutes am I supposed to be doing this for? The assignment gave me a variable called final int ITERATIONS = 1440 , could that have something to do with how long I loop? Secondly, what exactly do I add to the queue if the conditions are true. For example, if rand1 < LANDING_RATE/60, what would I enqueue to the landingQueue? Thirdly, how am I supposed to check if the runway is free? Does that mean check to see whether the takeOffQueue is empty or not? Fourth, would allowing the first plane to land mean removing an item from the landingQueue? Also, what does it mean by "otherwise, consider the takeoff queue". Does that mean if the landingQueue is empty, I should start removing items from the takeOff queue?
The biggest problem is the fact that I have to calculate the average queue length and average time that an airplane spends in a queue.
*Write a program to simulate this airport's operation. You might assume a simulated clock that advances in one-minute intervals. For each minute, generate two random numbers: If the first in less than LandingTime /60, a "landing arrival" has occurred and is added to the landing queue, and if the second is less than TakeOffTime /60, a "takeoff arrival" has occurred and is added to the takeoff queue*.
*Next, check whether the runway is free. If it is, first check whether the landing queue is nonempty, and if so, allow the first plane to land; otherwise, consider the takeoff queue. Have the program calculate the average queue length and the average time that an airplane spends in a queue.*
I have most of the code done as you can see below:
Right now, I am stuck on the first calculation which is trying to figure out the average size of the landing queue. For some reason, as you can see at the bottom of my demo program, the average always comes out to be 0.0 and I'm not sure what's wrong.
Secondly, how to calculate the average time a plane stays inside a queue for. Write a program to simulate this airport's operation. You might assume a simulated clock that advances in one-minute intervals. For each minute, generate two random numbers: If the first in less than LandingTime /60, a "landing arrival" has occurred and is added to the landing queue, and if the second is less than TakeOffTime /60, a "takeoff arrival" has occurred and is added to the takeoff queue.
Next, check whether the runway is free. If it is, first check whether the landing queue is nonempty, and if so, allow the first plane to land; otherwise, consider the takeoff queue. Have the program calculate the average queue length and the average time that an airplane spends in a queue.
I have most of the code done as you can see below:
Right now, I am stuck on the first calculation which is trying to figure out the average size of the landing queue. For some reason, as you can see at the bottom of my demo program, the average always comes out to be 0.0 and I'm not sure what's wrong.
Secondly, how to calculate the average time a plane stays inside a queue for.
My isEmpty method only returns false. Is something wrong? I printed the empty and not empty for testing purposes.
//determines if there are any items in the queue public boolean isEmpty() { if (front == -1 && rear == -1) { System.out.println("empty"); return true; } else { System.out.println("not empty"); return false } }
I have to implement all the stack methods in java such as push, pop empty, not using the ready methods but have to create them and to execute an exercise but is sth wrong with it
public class Stiva { /** the problem is here how to declare the stack 1 and stack 2 and kreu(head) gjmax(size)*/ int Gjmax; int array[] = new int[Gjmax]; int kreu; private Stiva stiva1; private Stiva stiva2;
I have to implement all the stack methods in java such as push, pop empty, not using the ready methods but have to create them and to execute an exercise but something wrong with it....
public class Stiva { /** the problem is here how to declare the stack 1 and stack 2 and kreu(head) gjmax(size)*/ int Gjmax; int array[] = new int[Gjmax]; int kreu; private Stiva stiva1; private Stiva stiva2;
My assignment is to design a simple GUI calculator using the stack data structure to perform additions, subtractions, multiplications and divisions. But i having error while i press the action there.
import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.util.*; import java.util.Stack; public class JCalculator implements ActionListener {
I have an error using quicksort and this is a project ... The error occurs for numbers such as 7500 and bigger ...
Exception in thread "main" java.lang.StackOverflowError at QuickSort.QuickSort(QuickSort.java:45) at QuickSort.QuickSort(QuickSort.java:46) at QuickSort.QuickSort(QuickSort.java:46) ...
Java Code:
import javax.swing.JOptionPane; public class QuickSort{ public static void main(String[] args){ int p=new Integer(JOptionPane.showInputDialog("Jepni numrin e kufizave: ")); int[] ListaNumrave= new int[p]; //QuickSort Zbrites
I have the following code to check for five characters palindrome but it always give me incorrect answer that if i have a word like radar the answer it isn't a palindrome. and if i changed any thing in the code i got either stack overflow or index out of bounds exception
The code is as the following
import java.util.Scanner; public class Palindrome { int first =0; static int n; int last = 4; int y = 0; public static void main(String [] args)
I recently have tryed to make a java code that reads words and say if its palindrome or not. I want to fix two things but unfortunately i can't do it on my own.
1st thing that i want fix is that when i run the code i have to press 2x times enter..and i dont know why?(i want one time to press it when i write the text)
2nd thing that i want to fix is that when you run it you can put as many words as you can..only when you write "END" the code must ends.
So unfortunately my code runs only for 1 time.(one word)
My code:
class test { public static void main(String args[]) { System.out.print( "#Enter text : " ); String text = BIO.getString(); String reverse = BIO.getString(); int length = text.length();
I'm supposed to use stacks (implemented with an array) to check to see if a string is a palindrome. I've finished all my classes and methods, but I'm getting an ArrayIndexOutOfBoundsException when I try to run my demo program.Here are my classes:
public interface Stack { // Creates an empty stack public void initializeStack() // Returns true if the stack is empty, returns false otherwise public boolean isEmpty(); // The stack can never be full, so always return false public boolean isFullStack();
I have to write a program that inputs a string and tests whether or not it is a palindrome. This worked fine, and now I want to make it so I continually enter strings until I tell the program to stop.
The code below compiles just fine, but it doesn't do what I want. Why it doesn't work how I think it should work? (Typing in STOP does not make the program stop.)
Here is the code
import javax.swing.JOptionPane; public class PalTest { public static void main(String[] args){ String S="pony"; while(S!="STOP"){ S=JOptionPane.showInputDialog("Enter a string (STOP to terminate):");
I cant figure out something in my code. I have to check whether given doubly linked list is palindrome or not. If it is palindrome it should print 1 , if not -1. My code has no errors but it always prints -1. I tried debugging but first comparisongives always false and function cant reach to else statement.
Are there any logical errors or i cant do right way of comparison?
import java.util.Scanner; class DLLNode<E> { protected E element; protected DLLNode<E> pred, succ; public DLLNode(E elem, DLLNode<E> pred, DLLNode<E> succ) { this.element = elem; this.pred = pred; this.succ = succ;
