I'm finding common elements in a collection of arrays. This is my code so far.
import java.util.ArrayList;
import java.util.List;
public class CommonElements //< T extends Comparable<T> >
{
Comparable[] comparable;
Comparable[] tempArr;
Comparable[] tempArr1;
Comparable[] newArray = new Comparable[tempArr.length];
int comparisonCount;
[code]....
I'm using this method to sort through my array. The method accepts a collection of arrays (of varying length and of any type) as input, the algorithm input should be no greater than n(k-1). I know I can solve it using a quadratic algorithm, but it won't meet the requirement of the assignment. I did have an idea of storing all my algorithm in one giant array. After storing as one giant array I was going to sort it. After sorting I was going to compare each array side by side and see if they are the same. Here is note my teacher provided.
Note About Testing You will need to develop several sets of test collections for testing your algorithm. The grading rubric mentions covering the case where all the test collections have the same length, as well as covering the case where the test collections are of different lengths. You will also need to think about what constitutes the worst case scenario for this algorithm, since only that scenario will make your analysis of total comparisons performed a meaningful one. You can use the formulas in the grading rubric to tell you how many comparisons you should expect in the quadratic and linear cases. For example, if you have 5 total collections (1 query collection and 4 test collections), each of which contains 10 elements, the total number of comparisons performed in the worst case should be: (k - 1)N2, which for k = 10 and N = 10 is: (5 - 1)102, or 400 comparisons. For the linear algorithm, you should only have N*(k - 1), which is 10*(5 - 1), or 40 comparisons.
Here is Q/A that my teacher provided:
1. Are the elements in the collections already sorted?The input collections may or may not be sorted. Don’t assume that they are sorted.
2. Can I sort the elements in the collections? Am I supposed to sort the elements in thecollections?Yes, you can sort the elements in the collections. It is not required that you do so, however..
3. If I sort the collections, should I count the element comparisons that are performed by the sorting algorithm?No. The only element comparisons you should count are the ones that are directly used to find the common elements. Ignore comparisons performed by any sorting algorithms you use.
4. How do I extract an individual collection from the Object[] collections argument of the findCommonElements method?You will need to typecast each collection as type Comparable[]. For example:Comparable[] currentCollection = (Comparable[])collections[i];
5. Why are we using a one-dimensional Object array instead of a two-dimensional array of type Comparable (e.g., Comparable[][])?In Java, arrays are treated as objects, so only a variable of type Object[] can contain arrays. A variable of type Comparable[] can only contain Comparable elements, not arrays. A variable of type Comparable[][] also can only store Comparable elements. Although it is possible to organize the elements such that all the elements at indexes [1][i], for example, are considered to comprise a collection, this is not the same as having an array that contains other arrays. The additional bookkeeping is required to keep a 2D array organized is more complex than simply performing the typecast described above.
6. Can I use other data structures besides arrays; e.g., HashMaps?No. Although it is easier from a programming perspective to use higher order data structures like HashMaps to find common elements, using these structures simply hides the details. If you were to examine the implementations of those structures, you would probably find that they use relatively inefficient algorithms such as sequential searches to find elements. Additionally, if you use library components, you have no way of counting the number of comparisons performed, since you don’t have access to the source code of those components.
7. Is this a trick question? I can’t think of any way to get below NlogN comparisons.It is not a trick question. It is possible to solve this problem using a number of comparisons proportional to (k – 1) * N.
The question states: Design a class named LinearEquation
for a 2 x 2 system of linear equations:
ax + by = e
cx + dy = f
Where
x =
ed − bf/ad − bc
y =
af − ec/ad − bc
The class contains:
- Private data fields a, b, c, d, e, and f. - A constructor with the arguments for a, b, c, d, e, and f. - Six get methods for a, b, c, d, e, and f. - A method named isSolvable() that returns true if ad−bc is not 0. - Methods getX() and getY() that return the solution for the equation.
Write a test program that prompts the user to enter a, b, c, d, e, and f and displays the result. If ad − bc is 0, report that "The equation has no solution."
I believe that my program is correct because I am able to compile it and get no errors, however I have no clue how to display the information for x and y or display this equation has no solution if ad-bc=0.
Java Code:
import java.util.Scanner; public class Exer911 { public static void main(String[] args){ // Create a scanner system to hold the numbers for each variable Scanner input = new Scanner(System.in); // Prompt the user to enter a number for each of the variables
I develop a finite element code at java. I am looking for efficiency solver and fast for large, sparse , symmetric and positive define matrices .
i used in jblas but i encounter in problem when the matrix has high condition number(ill condition number) and i get error for singular matrix while in mathematica i succeed to solve that system without problems...
Any good solver and fast solver package in java can i use for solving that system?
Design a class named LinearEquation for a 2 X 2 system of linear equations:
ax + by = e cx + dy = f Where x = ed − bf/ad − bc y = af − ec/ad − bc
The class contains:
- Private data fields a, b, c, d, e, and f. - A constructor with the arguments for a, b, c, d, e, and f. - Six get methods for a, b, c, d, e, and f. - A method named isSolvable() that returns true if ad−bc is not 0. - Methods getX() and getY() that return the solution for the equation.
[code].....
how to display the information I need to display. Also I am not so sure that I wrote the code properly, I do not get any errors when I compile it.
I am having some trouble with linear search of a customers last name. I can't seem to get it to work. I have looked up examples but cant find many with Array Lists. Here is my code.
import java.util.ArrayList; import java.util.Scanner; public class AccountDriver { public static void main(String[] args) { ArrayList<Account> al = new ArrayList<Account>(); ArrayList<Customer> cust = new ArrayList<Customer>(); Scanner scan = new Scanner(System.in);
I got this code from wikipedia when trying to learn about the radix sort algorithm now I understand that the algorithm sorts by significant digits but it's the code that I'm not too sure about for instance the series of for loops at the bottom what exactly is going on there and why is it mod by 10? Also why are there three different integer arrays a, b, and bucket?
public static void radixsort( int[] a, int n) { int i; int digit = 1; int[] b = new int[n+1]; for (i = 1; i < n; i++) if (a[i] > a[0]) a[0] = a[i];
So i was assigned to write a program that would print the answer to the system of two linear equation. the form of ax+by=c and dx+ey=f..I wrote this program, but it is incorrect since I tried it out on my terminal and I keep getting incorrect values.
import java.util.Scanner; public class Quest4 { public static void main(String[] args) { Scanner input = new Scanner(System.in);
I am attempting to find the element that holds the lowest time ( i have used System.currentMillisTime ) in the array using a linear search and to then print the times held by the array in lowest to highest order . While i understand how to do a linear search using user input as the key i am not to sure how to do it by initializing a search key in the program to the lowest number and have little experience in using a search in a program that is not a simply linear search. i have attempted to code this, as seen below, but i know i am definitely wrong and i have tried another of different ways even Array.sort and then a binary search .
static long store_MAX[]; // Now an ‘array’ of ints static int deptSize; // Holds the length of the buffer private int shopper_MAX; // Holds the number of items in the buffer
I have to write the Insertion Sort Algorithm using Java codes and at the same time find the time of execution for different sizes of array, filled with random numbers. If I try to show the numbers inserted into the array randomly, they don't appear at the console.
import javax.swing.JOptionPane; public class Insertion { public static void main(String[]args){ int SizeArr = new Integer(JOptionPane.showInputDialog("Enter the size of teh array")).intValue(); int [] r= new int [SizeArr]; {for(int d=0; d<r.length; d++)
I need a Java algorithm that converts a string of numbers into text. It is related to how a phone keypad works where pressing 2 three times creates the letter "c" or pressing 4 one time creates the letter "g". For example a string of numbers "44335557075557777" should decode where 0 equates to a space.
So I was just wondering if it's possible to create a program with JAVA that uses an algorithm to summarize data inputed. I've never done something like this before, If this is not possible with Java is it possible with C++ or any other language??
how to create a tree data structure in java.I tried with a class consisting of node field and arraylist child nodes. but it does not satisfy the requirement.the requirement is that,
I'm getting a DOMException, "HIERARCHY_REQUEST_ERR". I know that the problem is from the following code towards the bottom in my function, but I don't know how to deal with it. When I get rid of doc.appendChild(staff);, I get rid of the problem, but it obviously doesn't add the new entry to my root element.
Element staff = doc.createElement("Staff"); doc.appendChild(staff);
I want to create a TASK MANAGER for windows OS using java. Of course i am not expecting any code snippets, that is, what are the classes to be included and moreover HOW to do it.
Anyway I am creating a game for my A2 coursework, most commonly known as Checkers. I have completed my code and everything works as I had planned except that the CheckerBoard itself as well as the checkerpieces do not appear to be showing.
The section of were my board should be present is just a black space. Although my board does not appear to be displaying, all of the actions I perform on it such as clicking certain section produces the planned response, and although I've checked through my code I cannot work out what I've done wrong.
CheckerBoard content = new CheckerBoard(); // Sets the CheckerBoard values into the content to be used in the next line application.setContentPane(content); // Container holds the values together, Content pane of the CheckerBoard application.pack(); // Use preferred size of content to set size of application. Dimension screensize = Toolkit.getDefaultToolkit().getScreenSize(); application.setLocation( (screensize.width - application.getWidth())/2, (screensize.height - application.getHeight())/2 );
[Code] ....
I have noticed is that within the BoardComplete(), if you change the setBackground(Color.BLACK) to WHITE, it will change the colour of the section to white, but the checkboard is still unshown.
I just want to ask about a kind inheritance.Let say I have an interface MachineCode.I also have different classes, Binary, Hex and Octal that implements MachineCode
Question: How can I prevent java to create an Object like this:
Binary bin = new Binary(); Hex hex = new Hex(); Octal octal = new Octal();
those declaration above must be compile error,
I want to create Objects of Binary, Hex, and Octal this way: MachineCode bin = new Binary(); MachineCode hex = new Hex(); MachineCode octal = new Octal();
I am creating a Guessing game program in java code. I am having an issue with the guess class and main/tester class running. The instructions for the game are The computer generates a random # and the user must guess that number in 7 or fewer guesses. If the guesses exceed 7, then the game is over and the user is asked if they want to 'play again?'These are things I need to incorporate into my code:
If Statement
A Loop of some kind At least three imported methods At least two methods you create Obtains input from the user At least two instance variables At least two local variables Some form of concatenation At least two calculations
import java.util.Random; public class Guess { int computersNumber; // A random number picked by the computer. int usersGuess = 0; // A number entered by user as a guess. int guessCount = 0; // Number of guesses the user has made.
I would like to use java se api names like, undo, redo, stylededitorkit, htmleditorkit in editorpane swing. So, I don't understand how to use these apis.
I have a problem with slider which i want to create jlabels in a panel by sliding the slider and get the value but the jlabel doesn't show in jpanel. Below is the code :
JPanel PanelBoxes; JPanel panel; JLabel c; public static void main(String[] args){ DividePanel div = new DividePanel(); div.go();
I'm trying to create a tile based map JPanel but all I get is a white screen. I'm fairly new to the Java Swing and AWT package so I've been watching tutorials on YouTube so learn as much as I can. I don't know where I'm going wrong.
I've got three classes: Window.java which includes the Main method, Panel.java which is the JPanel and Tile.java to draw all the images into an array.
Window.java:
import javax.swing.JFrame; public class Window extends JFrame { public Window() { setTitle("Project"); setSize(500, 400); setLocationRelativeTo(null);
I have a java project in Eclipse. I make changes to this project from different computers. I think this is a good opportunity to learn and practice some source control. Is there a source control system which will allow me to do this very easily ? How about Git ? Any outline of the main steps needed to setup this thing with Git, preferably within eclipse itself ? I don't need each and every step to prepare the whole system. I only need the main steps like - download and install git on both machines, rent a server and create a repo on it, grant both computers access to the server etc.
I'm trying to create java based fairly simple forum.
The task is as following:-
• each user may post exactly one research topic;
• each each may see all research topics posted by other users;
• each each may read all messages contributed by all users on a particular research topic;
• each user may post a new message to contribute to the discussion on any of the topics posted.
Something like below:-
User topic: Intrusion Detection Systems Posted by: John [22/10/11 14:00] John wrote I am building a new IDS based on neural networks. …………….Comments ………….? [22/10/11 14:12] Kate wrote there could be too many false positives!