Reverse Double Linked List In Java - Descending Order
Sep 12, 2014
I have the following double linked list and I'm supposed to order it descending (reverse) using the printInReverse() method; since the list orders itself ascending when the numbers are added, how could I order it descending in this method? Here's the code without implementing descending/reversing methods:
I wrote displayAscending() and displayDescending() methods to this double linked list and it is not working at all. Logically it seems fine to me. I positioned the head in the beginning in the ascending method; created a variable named data1 as an auxiliar variable so it can store the values that are going to be moved; and moved the values. Same thing for the descending method but instead of the head I put the tail and move left the list, instead of right.
import java.util.*; class node { int data; node left; node right; node(int d, node l, node r) { data = d;
I am creating a recursive method to reverse a linked list in java. It works the first time when I call it, but I want it to work where I call it a second time and it reverses it to the original state. How can I get that to work with this implementation?
public void reverseList() { System.out.printf("%-16s%-3s%n", "Name", "Score"); System.out.println("--------------- -----"); reverseList(first); } public void reverseList(Node aNode) { if (aNode != null) { reverseList(aNode.next); System.out.printf("%-15s%6s%n" , aNode.name , aNode.score); } }
i tried everything but its giving me errors. i tried the for loop but its giving me something else.
this is what i have to do Write a recursive method that prints out the data elements of a linked list in reverse order.
Your method should take in as a parameter the head reference to a linked list. Then, write a recursive method that returns a count of the number of elements greater than a given threshold. You may assume that the data elements in the linked lists are ints. The parameters of your method are a reference to the linked list and a int value representing the threshold.
public class recursion3 { public static void main(String [] args) { char a [] = {'A', 'B','C','D','E'}; System.out.println(a); } public static String reverseString(String s) { if (s.length() <= 1) {
I've been stuck for the last couple hours trying to understand why the "printInReverse" method is getting into an infinite loop. I was supposed to make a double linked list that you can insert numbers and it orders both ascending and descending; in this case, descending is the "printInReverse" method, which takes the already ordered lists and prints it reversed, like if it was descending, and that's where the problem lives. Here follows the whole code:
My homework is a Double Circular Link list and when i write implements Iterator it gives me a an error when I compile it the same for my subset method...
ERRORS :DoublyCircularList.java:55: error: DoublyCircularList.iterator is not abstract and does not override abstract method remove() in Iterator public class iterator implements Iterator<T> ^ Note: DoublyCircularList.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. 1 error
import java.util.Iterator; public class DoublyCircularList<T extends Comparable<T>> extends LinkedList<T>implements Iterable<T> { Node<T> first; int size; public DoublyCircularList(){ first = null; size = 0;
I am currently making a double linked list class in my compsci class. i was absent for a few days and i need to make an add method for the class. when i go to compile test code i made i get a null pointer error on line 36. This is the node class i wrote and the double linked list class i wrote.
node class
public class Node{ // Two references and Data Node prev; Node next; String data; public Node(){ prev = null; next = null;
[Code] ....
This is the class i need working with ( in the doublelinkedlist class)
This is what I have to do:Write a program that takes a string of someone's name and prints it out last name first. Your program must use pointers, not array subscripts. You may use the available string manipulation functions if you find an opportunity.
Example:
"George Washington" "Washington, George"
I am not sure how to reverse the name, I have been looking in my textbook and online and cannot figure it out. This is what I have put together so far, it does not run. At the end it says unnecessary return value.
import java.util.*; import java.util.Scanner; public class Test { public static void main ( String [] args ) { Scanner sc = new Scanner(System.in); System.out.print("Enter name: "); String name = sc.nextLine(); String lastname = ""; String firstname = ""; for(int i = 0; i < name.length(); i++) { if(name.charAt(i) == ' ')
I am trying to create a java program to sort an array in ascending and descending order. Here is the program I created :
import java.util.Arrays; import java.util.Collections; public class ArraySort { public static void main(String [] args) { int [] num = {5,9,1,65,7,8,9}; Arrays.sort(num);
[Code]...
BUT I GET THE FOLLOWING EROOR ON COMPILATION
ArraySort.java:12: error: no suitable method found for reverseOrder(int[]) Arrays.sort(num,Collections.reverseOrder(num)); ^ method Collections.<T#1>reverseOrder(Comparator<T#1>) is not applicable
I had to make a program that allowed the user to enter the number of students and the students names and grades and then print out the name with the grade in descending order. right now I only have it where it prints the names out in descending order. how do I get it the print out with the grade?
Here is my code
import java.util.*; public class Grades { public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.print("Enter the number of students: "); int numofstudents = input.nextInt();
I want to write an application that inputs a sentence, tokenizes the words with method split and reverse the words (not the letters)...I am stuck at the last part: how to reverse them...should I use the method reverse(); ?
Here is my code..
import java.util.Scanner; import java.util.StringTokenizer; public class ReversedWords { //execute application public static void main( String [] args) { //get sentence
I'm trying to make this code's output display like a sentence, since right now it displays downward and doesn' look right.
public class ReverseOrder { public static void main(String[] args) { String phrase = "The rain in Spain falls mainly on the Plain"; char[] phraseArray; phraseArray = phrase.toCharArray(); for(int i = phraseArray.length - 1; i >= 0; i--){ System.out.println(phraseArray[i]); } } // end main } // end ReverseOrder class
Write an application, HiFour that prompt for four names and then prints the greetings, but with the names in reverse order and with punctuation as shown in the example.
public class ReverseOrder { public static Scanner input = new Scanner(System.in); public static void main(String[] args){ int[] numbers; double[] reverse;
I am creating a josephus java program with a circular linked list.This is what the methods are suppose to do
a. size(): Returns the number of items in the list.
b. isEmpty(): Returns true if the list is empty and false otherwise
c. advance(): Moves the cursor from the current position to the next item. If the cursor is at the end (tail) of this list, calling advance() should make the cursor refer to the first element in the list. If the list is empty, this operation should have no effect.
d. getCurrent(): Return the String value in the node referenced by the cursor unless the CircularLL is empty in which case write an error message to System.err.
e. add(String data): Adds a new item to the list by creating a newNode and linking it to the end of the circular linked list. The last node should point to the new node and then you should make lastNodeInserted point to new node as well.) Please note that a circular linked list is always circular. The last node should point to the beginning node. When there is only one node in a CircularLL, its next should point to itself. This method updates currNode when the first node is added, and always updates lastNodeInserted and numNodes. Take care when adding the first node this is a special case and should be handled differently.
f. remove(): If the list is empty, write an error message to System.err indicating that an attempt was made to remove from an empty queue and return null. Assuming the list is't empty, this method removes the node currently referenced by the cursor, reassigns the cursor to point to the next node in the list, and returns the String value stored in that node. To keep the list linked, you'll need to locate the previous node to the one youre removing and connect its next to the node which follows the one youre removing. Create a local Node variable (prev) to find it. Consider and handle the special case when there is only one node and youre removing it. And make sure to update lastNodeInserted whenever you remove the node that it is pointing to.
g. toString(): This should return a String representation of the circular linked list, with the first value displayed being the data of the first node added (not the data in the last node).
public class CircularLL { private class Node { String data; Node next;
public Node(String data) { this.data = data; this.next = null;
I've playing around with linked lists and methods for sorting. So far I've tested the iterative sort, insertion sort, quick sort and they all worked perfectly. Now, I am trying to implement merge sort that would take a linked list of jobs and sort them according to their priority. I found a few solutions on the web, of which I am trying to implemented this one: LeetCode.
My system is a simple one, I do have a linked list of print jobs, each of which has the priority. The following code should sort my print queue and return the link node of the first sorted element. Here's the code.
//defining a job that has priority public class Job { private int priority;
[Code]....
The problem I've been trying to solve is that I am getting the stack overflow at line
ListNode<T> h1 = mergeSort(left);
meaning that I am getting into a loop somewhere down through the process of breaking the linked list into half, half or halfs and so on.
I have a college question ask me to write a class StringRevert which does the following:
-prompting user for an interger n -creating an array of n string -repeatedly read character string from user input and store them in the array until end of array is reached or user input -quit(quit should not saved in array) -print the string from array in reverse order, from last enter to first enter. -assume user always supplie correct input
This is what I've done so far but how to get it working.
import java.util.Scanner; public class StringRevert { public static void main(String[] args) { Scanner in = new Scanner(System.in); System.out.println("enter value of n: "); int n1 = in.nextInt(); String[] n = new String[n1];
Create a class that allows the user to select a file and output the contents of the file to the console. Recommend using a text file to display, java files are text files. You may want to put this code in a method to allow you to complete the remainder of this assignment without overwriting your code.
- You should ask the user to enter the full path to your file to make certain you are processing the correct file.
- Modify your code/add a method to display the contents of the file in reverse order. You do not need to reverse the characters on each line but simply output the lines of the file in reverse order.
Hint: read the content of the file into an ArrayList and then traverse the ArrayList.
this is what i go so far.
package classActivity;
import java.io.File; import java.io.FileNotFoundException; import java.io.PrintWriter; import java.util.ArrayList; import java.util.Collections; import java.util.Scanner; public class Select { public static String enterFilePath()
I'm trying to build a program that contains the ability to:
(1) insert new node at head, (2) print out contents of the list in order, (3) remove first node from head, (4) remove last node from tail, (5) find a target value, (6) give total number of occurrences of a target value, and (7) give total number of items in list.
The areas I'm struggling with implementing are: (
- remove from tail - I know how to find the final node but I can't quite figure out how to set it to null since its initial type is an integer. - find a target value - how to make the parameters quite workout so the user can simply input an integer value. - The solution is probably really simple but I can't figure out how to print out the results of these methods when I call them.
public class Node { private int data; private Node link; // Node Constructor 1 public Node() { data = 0; link = null;
Write a Java program that asks the user to store 10 numbers in an array. You should then print the array in the order entered and then print in reverse order. However, instead of putting all the information in the main, you should use a class called PrintIt. The PrintIt class should have an instance variable that is an array to hold the numbers. You should have a method that will print the array in the order entered. You will also need a method to print in reverse oder. Then create a tester class that asks the user to enter 10 numbers and puts them in an array.
So far I've got this.
public class printIt { int i; int [] numArr = new int [10]; public printIt () { i = -1;
[Code] .....
Output:
Enter a number:
8 34
Forward:
8 34
Reverse:
34 8
end
what i want as an number is being able to print out 10 numbers but this only lets me do two numbers. Why is that so?
I am trying to do this assignment but I can't get the needed output.
Create a program that asks the user how many floating point numbers he wants to give. After this the program asks the numbers, stores them in an array and prints the contents of the array in reverse order.
Program is written to a class called ReverseNumbers.
Example output
How many floating point numbers do you want to type: 5
Type in 1. number: 5,4 Type in 2. number: 6 Type in 3. number: 7,2 Type in 4. number: -5 Type in 5. number: 2
Given numbers in reverse order:
2.0 -5.0 7.2 6.0 5.4
Java Code:
import java.util.Scanner; public class apples { public static void main(String[] args) { Scanner reader = new Scanner(System.in); double[] numbers;
Write a java program to store employee information in a linked list, the program should implement the following functions:
The program should display the list of functions, and ask the user to enter the number of function that he/she wants to do, then perform the function as it is required in the previous table.
import java.util.*; public class Employee { Scanner in = new Scanner(System.in); String Name; String Address; String Department; int ID; int Salary;
[code]....
this is my out put
Please choose a number: 1-Add a new employee 2-Update employee's info 3-Remove employee's info 4-Exit 1 Enter name: Enter address: 2 Enter department: 3 Enter ID: 4 Enter salary:
now:
1- why are not my adding coming out in the output only the Enter name & Enter address ??
2- how can I add names and ID's and information to test that program
