I have about 100,000 (N) random long variables in an array. I'd like to find if any two longs are equal; they're not expected to be. At this size, should I use the Hashtable or brute force it at a cost of N^2/2?
View RepliesBasically this code is supposed to create an int array of 50 elements, then pull the elements listed in positions 1-6 to make a lottery draw.
Problem is it gets down to that last "For" statement and then says "duplicate local variable i." If I attempt to separate it from the previous for loop with curly braces, then it gets mad and says it doesn't know what "local variable i" even IS. So I tried changing it to "j" in the last statement and it couldn't recognise that either. I feel like I need to change the variable name in that second for loop but I'm not sure how to make it understand that the second variable is going to be outputting the values from the first variable.
public class Lottery {
public static void main(String[] args) {
// TODO Auto-generated method stub
int []nums = new int [50];
for (int i = 1; i <50; i ++) {nums[i] = i;}
[Code] ....
I have this code which suppose to sort files by their length and return a string[] of th file names:
import java.io.File;
import java.util.ArrayList;
public class SizeOrder extends SuperOrder {
public String[] sortArray(File[] pathList) {
File[] absoluteOrderFiles = this.absoluteSort(pathList);
ArrayList<File> sizeOrderList = new ArrayList<File>();
[code]...
Now, in the following line: absoluteOrderFiles[absoluteIndex].length() < sizeOrderList.get(sizeIndex).length()
I need to use the compareTo which only exists in Long object.
How do I convert primitive long to Long?
and is it possible to do it in a single line?
So I need to generate 10 random integers in the range 1-20 but i have to store them in an array called numbers. Then I have to call a method called displayArray which displays the contents of the array and for the assignment i have to use a for loop to traverse the array. The method header for the displayArray method is:
public static void displayArray(int[] array)
This is what I have done
public class RandomIntegers {
static int numbers = 0;
public static void displayArray(int[] array) {
System.out.println(numbers + "Numbers Generated");
[Code] .....
filling out a Random array: An Array of Specific Length Filled with Random Numbers This time what I need to do is take the elements from this Random array and assign them to a new Byte array:
for(int i = 0; i < limit-10; i++) {
Random dice = new Random();
int randomIndex = dice.nextInt(array.length);
if (array[randomIndex] < 128) {
System.out.print(array[randomIndex] + " ");
} else if (array[randomIndex] >= 128) {
System.out.print(array[i] + " ");
}
}
byte[] noteValues = new byte[]
{ 64, 69, 72, 71, 64, 71, 74, 72, 76, 68, 76 }; //This is the byte array filled manually!
I've tried amending the manual input to fit in with the Random array, as follows:
byte[] noteValues = new byte[]
{ array[randomIndex] };
In this case, however, the Byte array can't interpret the int values. Also, if the Byte array is outside the 'for' loop, array[randomIndex] cannot be resolved.
What the fastest way to sort an array of random integers. My instructor told me to look into an algorithm that uses 2n, but that is all he gave me. I am unable to find anything of the sort (pun intended there) on google, in my text, in my other java books or on here. The only thing that I have come up with are things like mergesort with the exception that the indicies of the Array have to be even. The program that I'm writing takes user input for a minimum to maximum range, the amount of numbers to fill the array in that range, and verbose.
I've tried bubbleSort but it takes forever to sort under the conditions below. I have seen a sorting algorithm that uses n (log n) but didn't really understand how that one worked.
Using the 2n algorithm, I should be able to test the range from 1 - 1000 and have it populate an array of of 1,000,000 random integers. It should be able to complete in a matter of miliseconds.
For a project we have to "shuffle" items in an array using random numbers. We are supposed to generate random numbers and use those numbers to exchange array elements. But I am not sure what that means, "exchange array elements". Does that mean you generate 2 random numbers within the length of the array, and then switch the items at those locations in the array?
View Replies View RelatedI am writing a program that creates an array with random numbers. Then the user can choose what number of the array he/she wants to check the occurance of. This works fine, but the numbers generated seems very weird, only 2 of the 10 possible numbers are generated. 0 and one of the other 9 numbers, the 0 is always 10100 and the other one is always 101.
import java.util.Random;
import java.util.Scanner;
public class OppgaveC {
public static void sjekk() {
int randomArray[]=new int[101];
int countArray[]=new int[10];
Random rand = new Random();
[Code] ....
it also says i have a memory leak on my scanner, ow can i close this?
I am having some problem accessing variables from an array instance of a class. Heres what i have done;
In the main class:
Example obj[]= new Example[4];
In the main class constructor:
obj[0] = new Example(0);
obj[1] = new Example(1);
obj[2] = new Example(2);
obj[3] = new Example(3);
In the main update() method:
if(condition)
//update
In the Example class constructor:
private boolean change = false;
In the Example class update() method:
if(x >20)
change= true;
Now, i want to access the variable change from the main class, how do i do it? The 'condition' in the if statement is the condition of wether the change variable ia true or false. How do i access it?
Suppose I have private static void name() { ... } that has a two dimensional string array named array[. Now suppose I have private static void different() {...} and I want to write a condition where if (item == array) { ... }, how can I access my array from name() when I am in different()? I get a compile error saying cannot find symbol. My code is similar to:
Java Code:
public static void main(String[] args) {
...
String item = keyboard.nextLine();
... }
private static void name() {
...
String[][] array = new String[1][5];
[Code] .....
I am having a hard time trying to figure out how to print random numbers from a an array list. I tried google but nothing worked. I have to pick certain values from two lists and print them on the screen. I have included comments in the code to facilitate the explanation.
import java.util.Random;
public class Parachute {
public static void main(String[] args) {
Random randomNumbers=new Random();
int number;
int array []={1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21};
char A[] = {'a', 'b', 'c','d','e','f','g','h', 'i','j','k','l','m','n','o','p','q'};
[Code]...
Trying to generate random integers, based off user-input for amount of integers, and then sort them into an array. The problem is that the second method needs to be int[] but I cannot figure out what to make the return result. The instructions say it needs to be an int[] in the UML diagram, so I know it's not supposed to be void.
Java Code:
public void generateNewSecret() {
Random rand = new Random();{
for (int i=0; i<numDigitsSet; i++) {
secretNumber[i]= rand.nextInt(10);
System.out.println("" + secretNumber[i]);
[Code] .....
I was inquiring about selecting random numbers from a Fibonacci array, the original post for which is here: Exiting a 'for' Loop Early. I have managed to achieve this with the following code:
System.out.println("Random numbers from the Fibonacci array");
for(int i = 0; i < limit; i++) //Limit is an 'int' of 15 & is set as the length of the Fib. array. I'm calling it for the Random array, too!!
{
Random dice = new Random();
int randomIndex = dice.nextInt(array.length); //The Fib. array was simply called 'array'!!
if (array[randomIndex] < 100)
{
System.out.print(array[randomIndex]+ " ");
}
}
When the code prints I get a random set of numbers which occur in the Fibonacci sequence preceding it. However, the actual length of this Random array also changes each time, and never more than the limit of 15 specified in the 'for' loop. What I want to try and do is print the Random array with a specific length each time. I've tried changing the conditional statement of the 'for' loop in different ways to set the Random array's length, but had no luck.
Write a program that creates an array that can hold 9 double values that represent baseball batting averages for a starting baseball lineup. Use a for loop to populate array with random double values in the range of 0.00 to 0.500. Recall that "double" values are what Java calls "real" numbers. Use a second for loop to print the values in the array with one number per line. Finally, use a third for loop to traverse the array and find and print the maximum batting average in the array. Note: you will need to use String.format to control the precision of a double number when you print it- Here is my code so far:
public class P2F {
public static void main (String[] args) {
double [] player= new double [9];
//player[0]= Math.random();
for (int index=0; index < player.length; index++) {
[Code] ....
When I open the terminal window I get different variations of this [D@4545c5]. I would like to know all the things I am doing wrong.
Im creating my 2nd project ever and its a hangman game. I created an Array that has 20 different words in it and need to create a function that generates a random number to pick a random index of the array to obviously pick a random word. I cannot figure out the syntax for the life of me.
View Replies View RelatedI am creating my 2nd project ever and its a hangman game. I created an Array that has 20 different words in it and need to create a function that generates a random number to pick a random index of the array to obviously pick a random word.
View Replies View RelatedHow do I compare an array (or maybe int?) (example: 3572) to a 4digit number from random generator? how many of the four digit match the generated numbers.
View Replies View RelatedI'm trying to generate random 100 numbers, from 0 to 9, in an array using Math.random, but it only outputs 0s which is very confusing to me. Also, I need to be able to count how many different integers there are like 0s, 1s, 2s... 8s, 9s.
Here's my code, I only got as far as the array then got stumped on the counting part.
import java.util.Arrays;
public class countDigits {
public static void main(String[] args) {
//Create random generator and values
int numbers = (int)(Math.random() * 10);
int arrayCount = 1;
[Code] ....
and my results
0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0
To simulate it, the program will generate a random number between 0 and 19, which represents the location in the array (i.e. index number). Then, the 3 numbers to the left and right of this location should be reset to the value 0. If there isn't 3 numbers to the left and right you may assume a lesser number depending on the boundaries of the array.
How to reset the numbers to 0 in the final array ?
This is my code:
public class rotate
{
public static void main(String[] args)
{
int[] arrayInput = {1, 7, 8, 6, 2};
for(int i = 0; i<arrayInput.length; i++)
[Code]...
It's printing out this (the second line):
I have a school assignment that involves me sorting an array of objects based on one of the class String variables. I am using as the title says a simple selection sort method. The problem I'm having is that when I run the program in debug mode, it never seems to enter the if statement in the inner loop. I would like to say I've tried a number of things to figure it out, but honestly I'm just stumped as to why it's not working.
Here is the code:
public static void sortTransactions(Transaction[] oTransaction){// This is the sorting method, obviously it's not done so it currently just prints to screen.
System.out.println("Successful call to sortTransaction()");
String min = "";
int curInd = 0;
Transaction[] temp = new Transaction[1];
[Code] ....
The output when I check to see if the array is sorted verifies that the array never does get sorted.
in my progrm there are three diff array of objects...namely garments..gadgets and home app...now one who buys from each of these sections will have to make a bill at last...when he choses to make the bill he will be shown the list of products he bought and their details (like price...brand...etc)...so i thought that while he orders each product(which is done in a previous method called purchase()...)....(each product is stored as an object in there diif arrays namely garments...gadgets ...appliances)....each of those object will be copied in a new array in a diif class...then that array print will give me the desired result...
is this approach correct...?and if its correct then how can i pull out a specific obj frm a stored array of object and then save it in a new array....?
My assignment is to write a program that will encrypt and decrypt a sentence entered by a user but the encryption is to be random using an array. Can I convert my sentence(string) from char to int then create a random array to encrypt?
import java.util.Scanner;
import java.util.Random;
/*SentenceEncryptionProgram
*/
public class SentenceEncryption {
string sentence; //sentence entered by user
[Code] ....
I have an array that I filled with 30 random characters, but now I am trying to sort them in ascending order and the descending order using lambda expressions.
public class RandomCharacters {
public static void main(String args[]){
Random r =new Random();
char myarray[] = new char [30];
for (int i = 0 ; i < 30; i++)
[Code] ......
Is my code right for this pseudocode:
<Declaration of the array for storing random integers and other necessary variables and / or constants. >
private int numbers;
private int max;
private int[] integer;
private Random generator;
public integer ( int n, int m )
[code]....
I need to create a program that draws random numbers and stores them in an array. How many numbers to be drawn is dependent on the array length, which is a parameter in the class constructor. (The entire array to be filled!) The program shall, however, just save the figures are not drawn already. (Ie, the array must contain only one instance of each numeral.) All figures drawn should be in the range of 100 to 1000, both limits included. These limits are defined as named constants. When all the numbers are generated and stored in the array, the program should find the largest, smallest and average value of the numbers in the array. In addition, it should find the value closest gjennomnstittetsverdien.
I have to random shuffle an array of Card Objects which does the funcion of a deck. Heres the code:
Java Code:
public void barajear(){
int j;
for (int i=0;i<52;i++){
j=Baraja.random(51);
if (this.mazo[j]==null){
this.mazo[j]=this.arreglo[i];
}else{
--i;
}
}
} mh_sh_highlight_all('java');
so bassically theres an array called "arreglo" which has the cards in order and the function "random" its an rng of numbers from 0 to 51.what i'm trying to do it's to take the cards from the ordenated array and put them randomly in the other but only if it's empty.(the array "mazo" has alredy been initialized with null).it worked at first, but now, after compiling succesfully i tried to run it and the cmd just...