How would I modify this version of a selection sort into a recursive method?
public static void selectionSortRecursive(Comparable [] list, int n)
{
int min;
Comparable temp;
for(int index =0; index < n-1; index++){
min = index;
[code]....
How would I modify this version of a selection sort into a recursive method?
public static void selectionSortRecursive(Comparable [] list, int n)
{
int min;
Comparable temp;
[code]....
I'm trying to make a selection sort method that will sort a list of Strings alphabetically.
I have a test list of Strings like so:
Joe, Steve, Oscar, Drew, Evan, Brian, Ryan, Adam, Zachary, Jane, Doe, Susan, Fred, Billy-Bob, Cindy, Mildred, Joseph, Hammer, Hank, Dennis, Barbara
However, whenever I run the method, the element that should go last, Zachary, in this case, ends up getting moved to the front for some reason. I'm not sure why.
I tried changing what the first element was initialized to, to the variable i as that would logically work as well, but it ends up missing the first element in the list.
Java Code:
public static void selectionStringAscendingSort (String[] words){
int i, j, first;
String temp;
for ( i = 1; i < words.length; i++ ) {
first = 0; //initialize to subscript of first element
for(j = i; j < words.length; j ++){ //locate smallest element between positions 1 and i.
if( words[ j ].compareTo(words[ first ]) <0 )
first = j;
}
temp = words[ first ]; //swap smallest found with element in position i.
words[ first ] = words[ i ];
words[ i ] = temp;
System.out.println(Arrays.toString(words));
}
System.out.println(Arrays.toString(words));
} mh_sh_highlight_all('java');
I have a question about selection sort. If I had an array of numbers, 1 2 3 4 100 0, and used the selection sort method (below) on the array,would the 0 slowly work it's way down to the end?
Nest loop = full rotation of nest loop
Nest loop 1: 1 2 3 4 100 0
Nest loop 2: 1 2 3 4 100 0
Nest loop 3: 1 2 3 4 100 0
Nest loop 4: 1 2 3 4 100 0
Nest loop 5: 1 2 3 4 0 100
Nest loop 6: 1 2 3 0 4 100
etc.
METHOD:
static void selectionSort(int[] arr){
int n = arr.length;
for(int i = 0;i<n;i++){
int min = i;
for(int j = i+1;j<n;j++){
if(arr[j]<arr[min]){
min = j;
}
}
int temp = arr[i];
arr[i] = arr[min];
arr[min] = temp;
}
}
Java Code:
import java.util.ArrayList;
import java.util.Random;
public class NumSorting {
public static int numOfComps = 0,
numOfSwaps = 0;
public static void main(String[] args)
[Code] ....
What is wrong with my code in this sorting program? It won't copy the random generated numbers to the sort method. How to get the random generated numbers to copy to the sort method. Below is what the program is displaying.
Original order : 3 2 5 4 1
Selection Sort
Original order:
[I@7a84e4
Number of comps = 10
Number of swaps = 0
Sorted order : 0 0 0 0 0
This time I am having difficulties with selection sort method, but not with the method itself (I think). So I need to sort an array and return the result of each step.
This is the main code:
public class Functionality {
public static int[][] selctionsort(int[] a) {
for (int i=0; i<a.length; i++) {
int least = i;
for (int j=i+1; j<a.length; j++)
[Code] ....
And this is the Test folder:
import static org.junit.Assert.assertArrayEquals;
public class PublicTests {
public static void main(String[] args) {
int[] a = new int[] { 35, 7, 63, 42, 24, 21 };
int[][] b = new int[][] { new int[] { 7, 35, 63, 42, 24, 21 },
[Code] ....
Now I am not sure what should I write in return since the 2nd (test) project has int[][] and in my main project I am working with int [].
I have this assignment to write a Merge Sort algorithm using recursion. To start I have a very tough time picturing what is happening when it comes to recursion, but I do understand how merge sorting works. At the moment I feel as though a very good portion of my code is correct, but I am having trouble with the recursion in the main method [ mergeSort(Queue<T> queue) ].
I have another 4 or so hours to pass in my assignment finished or not, and at this point I can honestly say I have no clue how to make my code work. I tried working through the problem on paper with a simple queue of size 3, but even that is a struggle. On paper my code works perfectly fine, so there is definitely something I am missing.
Below is what I have along with my JUnit test.
Java Code:
private Queue<T> output = new Queue<T>();
private Queue<T> output1 = new Queue<T>();
private Queue<T> output2 = new Queue<T>();
public Queue<T> mergeSort(Queue<T> queue) {
// TODO 1
if(queue.size() <= 1) {
return queue;
[Code] .....
I am trying to write a program that graphically displays a selection sort. It needs to sort bars of various heights, and the bars heights are generated from an array of random integers. The program needs to show the bars swapping as they are being sorted, I am having trouble getting the bars to draw, it needs to look like a bar graph. Here is my code thus far (not counting my boiler plate):
import java.util.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.Timer;
import java.awt.*;
import java.util.Random;
public class SelectionSortPanel extends JPanel
[Code] ....
Also right now it is giving an error from the compareTo method?
I have an arrayList with these values:
Mike Smith with a customer id of 100 has an account number of 1000 and a balance of $5,000.00
Hank Jones with a customer id of 101 has an account number of 1001 and a balance of $45,000.00
Sam Overstreet with a customer id of 102 has an account number of 1002 and a balance of $45,000.00
Hank Jones with a customer id of 101 has an account number of 1003 and a balance of $48,000.00
and so on .....
I am trying to do a selection sort by the account holders last name. I understand how to do if the Arraylist holds integers, but my arraylist holds multiple fields. I am not allowed to use collections as this is a homework assignment.
here is the Account Class
public class Account implements Comparable<Account> {
private int acctNum;
private double balance;
private Customer cust; // note we are putting a Customer object in the Account clas
private static int nextAcct = 1000;// used to keep track of the next available account number
[Code] ....
This is a lab for one of my CS classes, and the assignment is to create a randomly filled array (values 10-100) and use these values as the height of an array of rectangles (essentially a bar graph)that will be drawn on a page. After that's done, the code should use the selection sort method to sort the bars least to greatest, being repainted as it's sorted.
I'm receiving no errors, the original draws just fine, and the code sorts the first position and then...it just hangs. Like it's in an infinite loop but I have all of the modifiers in place (I think. I've been staring at this code for three days straight and I don't think I really see it anymore). I've tried talking to my professor and I get that her private life is really busy right now, but she just keeps blowing me off and I don't know what to do. Anyway, done with back story and whining so here's the code.
Rectangle class:
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class Rectangle
[code]....
Here is the code I have at the moment:
/**
* Use selection sort to sort the tracks by name. Return a new, sorted ArrayList of tracks.
*
* @return an ArrayList containing the tracks sorted by name, or null if no tracks exist
*/
public ArrayList<Track> getTracksSortedByName() {
// YOUR CODE HERE
if(tracks == null)
return tracks;
[Code] ....
Here are my 2 issues (there are 2 lines with compiler errors): I feel like I understand selection sort and binary search, but am not sure how to apply it to the more abstract idea of a Track ArrayList (hence the 2 compiler errors). What should I use to make it work. Lastly, I'm very uncomfortable with recursion, so my guess is there is also probably some logical issue with it in the getTracksSortedByName method.
I know it is possible to do this using the Array class but I don't want to use that. I am trying to use selection or bubble sort but I believe selection is what I want. This program asks the user to input 2 arrays with 10 integers each, sorts them from smallest to largest, then states whether they are the same or not. Comparing the two arrays.
import java.util.Scanner;
public class SetDifference
{
public static void main (String args[])
{
Scanner sc = new Scanner (System.in);
int array1[] = new int[10];
int array2[] = new int[10];
[Code] .....
Consider the following recursive method that calculates the greatest common divisor using Euclidean method.
PHP Code:
public static int GCD ( int x , int y )
{
if ( y == 0 )
return x;
else if ( x >= y && y > 0)
return GCD ( y , x % y );
else return GCD ( y , x );
}
Trace the above method for x=32 and y=46
I'm doing a project with very defined requirements. Input and output will be done to and from a file. Both the input and output files should have the same format. Each file will consist of a series of lines formatted as follows:
Year Rank Artist Title
That is, each line of the file will consist of the year, rank, artist, and title of a single song, with each of the fields separated by tabs ( ). Output files must maintain this format—you should be able to use the output file of one run of the program as the input to another run.
The first part of my project is to make a Song class, with 6 methods:
public static Song parse(String s) { //Parse a string of the form “Year Rank Artist Title” and create a Song object with the given values.
}
public int getYear() { //returns the year of the song
}
public int getRank() { //returns the rank of the song
[Code] .....
So far, I have worked out my Song class like this:
Java Code:
import java.util.Scanner;
public class Song {
private int year;
private int rank;
private String artist;
private String title;
[Code] ....
I know there's definitely a problem with my parsing, as I am getting the
Exception in thread "main" java.util.NoSuchElementException
when I attempt to input a test String at my variables.
Should I try using StringTokenizer and Integer.parseInt()? I think that perhaps the reason why an error is occuring is because the String is being parsed into Strings and there are no int values to be inputted into the year and rank variables.
Or is there a way to do this with Scanner?
As one of the methods of my IntTree tree I have to implement a method that multiplies the level number with the sum of the nodes on the current level. So far I have this, and it doesn't work. What I am wondering is am I on the right track at all with the second return statement?
public int depthSum(){
return depthSum(overallRoot);
}
private int depthSum(IntTreeNode root) {
if(root==null)
return 0;
int level = 0;
[code]....
I have this code and i want to trace it
public static int GCD ( int x , int y ) {
if ( y == 0 )
return x;
else if ( x >= y && y > 0)
return GCD ( y , x % y );
else return GCD ( y , x );
}
(it is a recursive method that calculates the greatest common divisor using Euclidean method )
while x = 32 and y = 46
I want here to understand how the code work ? Precisely , composition and decomposition operations.
I was told to write a method that adds up the sequence of the formula (n/2n+1) eg. 1/3 + 2/5 + 3/7 etc. simple enough i suppose. my method is below
public static double Series(int n){
if (n==0)return 0;
else return (n/(n*2+1)) + Series(n - 1);
}
However for some reason or another it returns 0 for any number that is put in. I've written it dozens of different ways with no change and i feel like something fairly obvious is being missed on my part. I am honestly intrigued and interested as to why this is happening. i assume it has something to do with the way i put the actual formula in cause if i put anything else in like simply n the recursion would work as expected.
KtMok1t.jpg
Below is what I go so far, but how to do star C and E.
public class PrintTriangle
{
public static void printStars (int star)
{
for (int number = 0; number < star;number ++)
{
System.out.print("*");
[Code] ....
I'm trying to understand the concept behind this recursive method called rangeSum. This method sums a range of array elements with recursion. I tried summing the elements of 2 through 5, and I tried writing down what actually happens when java executes the program, but what I get when I try to figure it out by paper is different from what netbeans gives me. Here is a snapshot of my scratch work as well as my source code. Netbeans gives me "The sum of elements 2 through 5 is 18" when I try running it but it I get 12 when I do the recursion on paper. I know that the source code is correct because it's out of the book but what am I doing wrong when I try figuring it out by hand?
XML Code:
package recursivecall;
import java.util.Scanner;
/**
* Author: <<Conrado Sanchez>> Date: Task:
*/
public class RecursiveCall {
public static void main(String[] args) {
[code]....
Write down a recursive method to remove vowels in string ....
View Replies View Relateda)Write a method that recursively displays any given character the specified number of times on one line.For example, the call: displayRowOf Characters(,5);
Produce a line: *****Write another method that uses a for-loop to perform the same process.
B is something like this ?
for (i=1; i<=n; i++)
i= '*' * n;
System.out.print(i);
I have 3 Xml documents that look like this:
model1:
Java Code: <?xml version="1.0" encoding="UTF-8"?>
<model>
<id>1</id>
<nodes>
<id>2</id>
<stencil>TASK</stencil>
</nodes>
<nodes>
<id>3</id>
<stencil>MODEL</stencil>
[Code] ....
After unmarshalling/marshalling in the main class I have created this 3 methods:
Java Code:
public List<Task> extractTasks(Model model) {
List<Task> tasks = new ArrayList<Task>();
for (ModelNodes modelNodes : model.getNodes()) {
if (modelNodes.getStencil().equals("TASK")) {
tasks.add(new Task(modelNodes.getId()));
[Code] ....
When the recursive call to the extractSubModels method is made, I get a **java.lang.StackOverFlowError** ...
I don't understand, why when in the constructor of the superclass A the method init() is called (line 4), the overridden version of the subclass is invoked (line 26) and not the superclass version (line 7):
class A {
public A () {
init();
}
public void init() {
System.out.println("test");
[Code] ....
I would have guessed that above code prints
test
1
But instead you get a NPE (because when the constructor of B is invoked
public static void main(String[] args) {
new B();
}
Then there is first the implicit call to super:
public B() {
s = " ";
init();
}
Which is the constructor of A:
public A () {
init();
}
But here now this init() method is not the version of A ( public void init() {
System.out.println("test");
}) but the overriden version of the subclass (B): public void init() {
System.out.println(s+=s.length());
}...
Which throws an NPE of course, because the initialization of s has not occured yet (it happens only after the implicit call to super() has finished (see public B() {
s = " ";
init();
}))
I am getting incombatable types, I do not know why I am getting them..why I am getting the error?
The Error I am getting:
stringSort.java:26: error: incompatible types
if(myArray[j].compareToIgnoreCase(myArray[i].toString())){
^
required: boolean
found: int
*/
[code]....
I have an ArrayList, based on the class which stores cricket players, their names and runs scored.When I use the Collections.sort() method my arraylist is sorted alphabetically by forename.how to OverRide the comparing method to sort by runs, and thus the code I use to sort the list?
View Replies View Relatedim trying to create an insertion sort method for a vector. I know how to insertionsort for an array, but for a vector im having problems
Source code:
PHP Code: package test;
import java.util.*;
import java.io.*;
public class LinearSearch {
public static void main (String[] args) {
Vector myVector = new Vector();
[Code]...
I'm getting errors at lines 38 and 39 "Left-hand side of an assignment must be a variable". "Syntax-error(s) on token(s) misplaces contructor(s)". How can i fix them ??