What Is Comparator In Sorted Set
Jul 11, 2014I read the document [URL] ....
But I am not able to get what is actual use of this in set ?
I read the document [URL] ....
But I am not able to get what is actual use of this in set ?
The code is meant to input 2 arrays (they must be sorted even if this is not verified ) and then merge them in such a way that a sorted merged array is created at the end.I need to avoid a simple concatenation and then sorting the resulting array operation.I m interested in what i m doing wrong .
The input i used was :
Enter list1:
5 1 5 16 61 111
Enter list2:
4 2 4 5 6
import java.util.*;
public class C7_31 {
public static void main(String[] args){
Scanner input = new Scanner(System.in);
[code]...
How to go through each link item in both lists, and directly link them into the new list in order without using insert()
class Link {
public long dData; // data item
public Link next; // next link in list
// -------------------------------------------------------------
public Link(long dd) // constructor
{ dData = dd; }
// -------------------------------------------------------------
public void displayLink() // display this link
{ System.out.print(dData + " "); }
} // end class Link
[Code] ......
I have an assignment and one of the prompts is to do a binary search on an array if and only if the array of Strings is sorted. The binary search part I think I have completed, but it is the sorted array check that is throwing everything off. If the array is already sorted, return true; else, return false.
// Check if the array is sorted
public static boolean isSorted(String[] arr) {
//for (int i = 0; i < arr.length-1; i++)
//{
//if (arr[i].compareTo(arr[i+1]) > 0)
//return false;
//}
String[] arrSorted = arr;
Arrays.sort(arrSorted);
[code]....
I am new to java or at least the collection series. My job is to make a method like this:
public void frequency(int[] arr)
And should contain numbers like: [ 2,5,2,9,7,1,100,2,3,5,77,9,1,2,6,5 ]
Now the next part i should sort the tabel and show how many times each number shows in the array:
with the index.
What is the best easiest way in collection?
I am trying to make a code that takes a list and puts the list in sorted order (least to greatest).
public class SortedIntList {
static final int capacity = 10;
private int [] data;
private boolean unique;
private int size;
public SortedIntList(){
size =0;
data = new int [10];
[Code] ....
Here what the code produces.
Testing SortedIntList()
error when adding these values to list: 4 6 4
list should = [4, 4, 6]
actual list = [4, 6, 4]
was working properly prior to adding last value of 4
I am trying to sort an ArrayList of objects with the comparator as I want to sort based on a certain value for each object. I understand I would need to override compareTo() in the objects class, is there any way I can get around also needing to override for all subclasses of the object?
View Replies View RelatedI am asked to create a code that if a user enters 1 it will use the object natural comparison form ('default') as written in CompareTo method.But if he chooses to enter something else then another comparison is used.Maybe I just need to use 2 diff comparators? but then what;s the point of defining something as 'default'....
View Replies View RelatedI have a small problem to solve by which I would like to merge 2 sorted maps into 1.
Map A
-------
Keys, Values
1, A
2, B
3, C
4, D
5, E
Map B
-------
Keys, Values
1, 10
2, 20
3, 30
4, 40
5, 50
Final Map should look like:
Keys, Values
A, 10
B, 20
C, 30
D, 40
E, 50
The final map would have all the values from Map A as a key and the values from Map B as values in the Final Map. Is there a way to do this using Java?
How do u copy all the elements in an array eg A into another array eg B? This is the question:
An array A contains integers that first increase in value and then decrease in value,
For example, 17 24 31 39 44 49 36 29 20 18 13
It is unknown at which point the numbers start to decrease. Write efficient code to code to copy the numbers in A to another array B so that B is sorted in ascending order. Your code must take advantage of the way the numbers are arranged in A.
This is my program:
This is the error message:
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException
at java.lang.System.arraycopy(Native Method)
at Quest30.CopyAndSortArray.main(CopyAndSortArray.jav a:16)
Write a program that promts a professor to input grades for five different courses for 10 students. Prompt the professor to enter only A,B,C,D, or F for grades(A is the highest grade, F fail). use variables for student number(1 through 10) and grade numbers(1 through 5). create a menu for Search. if the user select search it will prompt a letter correspond to grade. display all student with selected grade. if the user just enter nothing, display all student with their grade sorted from highest to lowest.
View Replies View RelatedMy problem is that I can't even run the program, because it gives me
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 13
at domashno.ten.longestSortedSequence(ten.java:37)
at domashno.ten.main(ten.java:17)
Code :
public static void main(String[] args) {
int[] arr = {3, 8, 10, 1,9, 14, -3, 0, 14, 207, 56, 98, 12};
longestSortedSequence(arr);
System.out.println(longestSortedSequence(arr));
}
public static int longestSortedSequence(int[] arr) {
[Code] ....
overriding of the compare method.
Here's an example I found:
public class Someone {
String name;
int age;
ArrayList <Someone> listarr = new ArrayList <Someone>();
public Someone(String name1, int age1) {
name = name1;
age = age1;
[code]...
1. In the compare method, what happens when it returns one of the 0, -1, or 1? How does returning such values contribute to the sorting process? How does it take in information (like I know it does through the parameters, but how exactly)?
2. Why do we use the class name for the generics?
Something about implementing Comparator interface isn't very clear to me: overriding the compare method.
Like here for example:
//This sorts a list of objects holding information based on age: the name and the age of the person
public class Person {
String name;
int age;
public Person (String name, int age)
{
this.name = name;
this.age = age;
[Code] ....
What exactly is happening behind the scenes? I don't understand mostly the part where it returns a 0, a 1, or a -1. After it returns one of those values, what really happens next?
For the displaying of the list, is the method toString() being accessed to output the list in the System.out.println statement?
For the generics, why do we use Person?
If an array has been sorted using a comparator then why is it necessary to pass on that comparator to the binaryserach method. What I want to know is that how come the presence of a comparator reference affect the way the algorithm works?
View Replies View RelatedI have a java code that should sort an array of names based on the last name. e.g jane a, jane b, jane z, jane d should be jane a, jane b, jane d, jane z. I have the following code but for some reasons, the s1 in the comparator method is always null.
public class ShuffleName {
public static void sortNames(String[] names){
Arrays.sort( names, new Comparator<String>() {
public int compare( String s1, String s2 ) {
String s1last = s1.split("s+")[1];
String s2last = s2.split("s+")[1];
return s1last.compareTo(s2last);
[code]....
Which of the following classes uses Comparable and Comparator?
QueueTreeSetStackPriorityQueue
In the above question, what does 'uses' mean? Does it mean do above classes implement Comparable and Comparator?
I know that in order to compare any two elements stored in one of the above classes, we need to make the elements' class to implement one of these - either Comparable or Comparator.
I was going through some lectures online and found that to compare or even swap, the use of comparable or comparator argument like
public static boolean less(Comparable v,Comparable w)
{
return v.compareTo(w)<0;
}
public static void swap(Comparable []a,int i,int j)
{
Comparable swap=a[i];
a[i]=a[j];
a[j]=swap;
}
I did not get the use of passing Comparable or Comparator to the function as parameters. Object as parameter could have been used too?
Is it possible to compare 100 objects using comparator interface in java?
View Replies View RelatedSo I built this comparator exactly the same way I built my others that are working.But the comparator for UserComparator is not being found for some reason.I will post my usercomparator class and JSP page.
<%@page import="tickets.UserComparator"%>
<%@page import="tickets.User"%>
<%@page import="tickets.ReporterTTComparator"%>
<%@page import="tickets.StatusTTComparator"%>
<%@page import="tickets.SystemTTComparator"%>
<%@page import="java.util.Collections"%>
<%@page import="java.util.ArrayList"%>
<%@page import="tickets.TroubleTicket"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
[code]....
The initial output of the texfile is this. NO ARRAYLIST OR COMPARATOR IS ALLOWED:
Steve Jobs 9 f 91
Bill Gates 6 m 90
James Gosling 3 m 100
James Gosling 3 f 100
Dennis Ritchie 5 m 94
Steve Jobs 9 m 95
Dennis Ritchie 5 f 100
Jeff Dean 7 m 100
Bill Gates 6 f 96
Jeff Dean 7 f 100
Sergey Brin 27 f 97
Sergey Brin 22 m 98
The collateExams method collates/sorts exam objects starting with the first 'm' (midterm) of the first object and immediately followed by the same person's 'f'(final). Only a SINGLE loop construct is allowed. The output from collateExams() should be the one below but my code is not working, i.e. collateExams method is not working. The output from collateExams() should be
Bill Gates 6 m 90
Bill Gates 6 f 96
James Gosling 3 m 100
James Gosling 3 f 100
Dennis Ritchie 5 m 94
Dennis Ritchie 5 f 100
Steve Jobs 9 m 95
Steve Jobs 9 f 91
Jeff Dean 7 m 100
Jeff Dean 7 f 100
Sergey Brin 22 m 98
Sergey Brin 27 f 97
I am getting [b]NullExceptions[/b] at
r[2*position[exams[i].getID()]+1] =
new Exam(r[i].getFirstName(), r[i].getLastName(),
r[i].getID(), r[i].getExamType(), r[i].getScore());
import java.io.*;
import java.util.*;
[Code] ....
Ok here are my 2 Classes
Both have Identical Fields
package com.Lists;
public class EmployeeOffice implements EmpInterface {
private double salary;
private String name;
private String postion;
private double hoursWorked;
[Code] .....
So if i wanna sort this Generic class using comaparator what do i do... I cant find an answer to this... I wanna sort them on the basis of salary what to do ...