So I'm trying to implement a quick sort method for an ArrayList of Strings and right now I'm getting the compiler error message: Exception in thread "main" java.lang.OutOfMemoryError: Java heap space. I don't know what that error means nor how to fix it. I've marked in my code where the error seems to be occurring.
import java.util.ArrayList;
public class quickSort
{
// constructor
public quickSort()
[code]....
I have wriiten a quick sort algorithm. I have used the last element as my pivot. The program is running for all sizes except for 100000 and 1000000 elements when they are sorted and unsorted list .
It shows me the error : Exception in thread "main" java.lang.StackOverflowError
I guess the memory gets out of space and we need to increase the stack size in eclipse. How do I increase the stack size in eclipse.? I tried increasing through run--run configurations-- program arguments and typed---- -Xmx4096m but this didn't work in any way.
I have to count the comparisons in the quick sort. I have done it by using a global variable. But I am stuck in doing it recursively.
This is my code.
import static java.time.Clock.system;
import java.util.Arrays;
public class test {
/**
* The swap method swaps the contents of two elements in an int array.
*
* @param The array containing the two elements.
* @param a The subscript of the first element.
* @param b The subscript of the second element.
*
*/
[Code] .....
I am using a static method to convert a string to an Integer object. Next using a instance method to convert Integer object to an int.
Compiler is giving me two "cannot find symbol" errors:
One pointing to the dot operator between "Integer.valueOf(s)"
The other pointing to the dot operator between "obj.intValue()"
I have latest JDK installed: jdk-7u51-windows-x64.exe
Looks like JCL installed correctly with rt.jar file located in "lib" directory under "Program Files"
Following is source code:
Java Code:
public class StringToInt
{
public static void main (String args [])
{
String s = "125";
Integer obj = Integer.valueOf(s);
int i = obj.intValue();
i += 10;
System.out.println(i);
}
} mh_sh_highlight_all('java');
I'm doing an exercise we're you're supposed to sort strings in alphabetical order, without importing anything , not using the Arrays.sort() method.
I think I got the method down partially right, or it is on the right track, but it is completely not being applied to my answer. All it prints out in the console is the actual String array twice, without sorting anything.
public class arrayofstrings {
public static void sort(String[] a) {
String temp= "";
int min;
int i= 0;
for (int j=0; j<a.length-1; j++) {
[Code] ....
An example from the SCJP(OCP) book:
Java Code:
class Animal {
void makeNoise() {System.out.println("generic noise"); }
}
class Dog extends Animal {
void makeNoise() {System.out.println("bark"); }
void playDead() { System.out.println("roll over"); }
[Code] .....
The book states that the above code will compile if there is a downcast in the line 14 . But there is a compiler error saying playDead method is not defined for type animal even after downcasting.
I have started to learn JAVA and was referring Head First JAVA book.
I have 3 separate .java files - GuessGame.java , Player.java, GameLauncher.java
I have successfully compiled GuessGame.java & Player.java
But I am getting an error when I am compiling GameLauncher.java.
public class Main {
private static void foo(Integer a) {
System.out.println("Integer");
}
private static void foo(long a) {
System.out.println("long");
[Code] ....
This code prints long. Why is that? How did compiler decided that it likes long version of foo() method the most. If I had to guess I'd pick int... or possibly Integer as they are most similiar to what was passed. But why long?
How can i sort my ArrayList, which contains cars, with year and used year, i want to sort them first from year, and then from used year . what should i use?
View Replies View RelatedIm trying to do an insertion sort using ArrayLists and I keep getting this error after the sorting section where it doesnt sort anything at all, but still displays my previous array list.:
Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 7, Size: 7
at java.util.ArrayList.rangeCheck(Unknown Source)
at java.util.ArrayList.get(Unknown Source)
at Utilities.insertionSort(Utilities.java:102)
at Utilities.main(Utilities.java:66)
My code:
import java.util.*;
import java.lang.*;
public class Utilities {
public static void main(String[] args) {
ArrayList<String> equipment = new ArrayList<String>();
[Code] ......
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] ....
We haven't covered BufferedReader in this course yet. The assignmen is to get user input to fill arraylist with strings then when user hits Enter without any input, the console displays the contents of the arraylist.
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
public class Ex01 {
public static void main(String[] args) throws IOException {
[code]....
I have a project where I must sort a collection of songs by a number of fields: year, rank, title and artist. in the project, we must use certain methods and we cannot add others without getting marked down. Here are the specific requirements:
Sorting
The -sortBy option will cause the output to be sorted by a particular field. If this option is specified, the output should be ordered according to the field named. If there are ties, the tied songs should appear in same order in which they were in the input file. If no -sortBy option is specified, the output should maintain the order of the input file.
public void sortYear()
Order the songs in this collection by year (ascending).public void sortRank()
Order the songs in this collection by rank (ascending).public void sortArtist()
Order the songs in this collection lexicographically by artist (ascending, case-insensitive).public void sortTitle()
Order the songs in this collection lexicographically by title (ascending, case-insensitive).
Here is the relevant code:
SongCollection Class
Java Code: import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.*;
[code]....
What I'm trying to do here is to count the vowels in an arraylist of strings. What I did may not be right, but that's not my problem for now. My problem is that i cannot return the value (n) I want to return. I don't know why.
import java.util.*;
import java.util.Arrays;
public class One {
public static void main(String[] args) {
ArrayList<String> list = new ArrayList<String>();
list.add("aaa");
list.add("brr");
list.add("unn");
System.out.println(vowels(list));
[URL] ....
I am advised to use a while loop the Scanner method hasNextLine() and in the while loop body, call the Scanner method nextLine(), and add the returned String to the ArrayList of Strings. what I have gotten so far:
Scanner input = new Scanner(new File(""));
while(input.hasNextLine()) {
String line = input.nextLine();
System.out.println(line);
I have been trying to get this method to work for a few hours now, for some reason I get an IndexOutOfBounds exception every time. Basically I am trying to read a txt file and add the words to an ArrayList as strings separated by a space .
private ArrayList<String> readLinesFromFile(BufferedReader inputFile) throws IOException
{
String value = null;
ArrayList<String> result = new ArrayList<String>();
while((value = inputFile.readLine()) != null){
String[] values = value.split(" ");
for (int i = 0; i < values.length; i++){
result.add(values[i]);
}
}
return result;
}
I was writing a code to have the library books classified in name, author, area, ed, etc. I'm using NetBeans and it doesn't accuse any error. But when I run the project, it never goes right and shows the books only in one area, regarthless what I type. (The goal of the algorithm is to separate the books in areas (sciences, humanities and biological science).
View Replies View Related i'm currently going over single linked list, and i'm coming across an error which i do not know how to get by. I'm using single linked list for now just for study purposes, then i would move on to double.
Error: No enclosing instance of type LList is accessible. Must qualify the allocation with an enclosing instance of type LList (e.g. x.new A() where x is an instance of LList).
public class LList {
private static class Node<E>{
private E data;
private Node<E> next;
[code]....
I am catching an error in my driver class that reads from a file and sorts the data based on a person's GPA. Here is my code:
import java.io.*;
import java.util.*;
public class Driver {
public static void main(String[] args) {
new Driver(args[0]);
[Code] ....
Why throwing this exception?
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'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;
}
}
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 ??
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]....
I have been looking around and I cannot seem to find which algorithm java uses for its sort method. Merge, sort etc.
While I am on the topic BinaryTree is a balanced heap right?
Are there any libraries for depth or breath first search?
Is the ArrayList a double linked list?