Weed Out All Prime Numbers Without Using Any Kind Of Division?
Dec 15, 2014
The challenge is to weed out all the prime numbers without using any kind of division (%, /). My code doesn't weed out certain numbers, such as many multiples of 5, the number 49, etc, and I am not sure why. Here is my code.
My logic for the for loops was this: Starting with the upper numbers of the ArrayList, find every number that is a multiple of that number and remove it from the ArrayList. Every time you find a multiple, increase the variable multiply, so the program knows what the next multiple to look for.
// program doesn't work yet.
import java.util.ArrayList;
// import java.util.ListIterator;
public class Sieve2
{
public static void main(String[] args)
{
int upperLimit = 55;
ArrayList<Integer> primes = new ArrayList<Integer>();
I tried to create file and write the output of my program in it in java when i use WriteLong then the file does not contain long value, how I create this file my program is to print prime numbers between 500000 to 10000000
public class primenumber { public static void main(String[] args) { long start = 5000000; long end = 10000000; System.out.println("List of prime numbers between " + start + " and " + end); for (long i = start; i <= end; i++) { if (isPrime(i)) { System.out.println(i);
Program is to list all prime numbers between two entered numbers.
import java.util.Scanner; public class question6 { public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.println("Enter lower int:"); int x = input.nextInt();
The assignment is to make a program that prints the number of prime numbers in a range. This is what i have so far. The output is a list of 2s. I created the for loop to cycle through the range of 17-53 and nested a while loop within to test each incident of the for loop to check for divisors starting with 2 until the modulus result is 0 resulting in a false for being a prime number. Then the loop should increment to the next i value. The last part is an if statement that i had intended to add counters to the k variable that would keep track of the number of prime numbers.
boolean isPrime = true; int j = 2; int k = 1; for (int i = 17; i <= 53; i++){ { while (i % j == 0){ isPrime = false;
public static void main(String[] args) { Scanner scanner = new Scanner(System.in); System.out.println(" Enter the maximum number "); int maxNumber = scanner.nextInt(); int[]numberList = createList (maxNumber);
[code]....
I have a problem with the output. It only get as far as marking the multiples of 2. It does not mark the multiples of 3 and so on.Example output: If the range is from 2 to 15 the output is :2, 3, 0, 5, 0, 7, 0, 9, 0, 11, 0, 13, 0, 15 note: 0 means its marked.As you can see it only marks multiples of 2 but it does not mark multiples of 3 above. I think the problem lies in the for loop inside my main method, because the index does not increment.
Program to pull prime numbers between two entered values,
import java.util.Scanner; public class question6 { public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.println("Enter lower int:");
I want to find the prime palindrome numbers less that a given number by my program. Here is my code, I am trying to find the method to solve the errors when I compile it. It said variable a might not have been initialized in line 41,62,86.
import java.util.Scanner; public class Lab5{ public static void main (String[] args){ System.out.println("Please input a number"); Scanner Input=new Scanner(System.in); int num = Input.nextInt();
the prime numbers from 1 to 2500 can be obtained as follows. From a list of the numbers of 1 to 2500,cross out al multiples of 2 (but not 2 itself). Then, find the next number (n, say) that is not crossed out and cross out all multiples of n (but not including n).
Repeat this last step provided that n has not exceeded 50 (the square root of 2500). The numbers remaining in the list (except 1) are prime. Write a program which uses this method to print all primes from 1 to 2500. Store your output in a file called primes.out.
The game doesn't seem to be working but you can win by loading a winning saved game.
Hint: Remember that all numbers have a unique set of Prime Factors.
I have been struggling to solve this. The code is not in error. I am trying to load a winning file but unable to solve.
Here is the java code:
import java.math.BigInteger; import java.util.ArrayList; import java.util.HashSet; import java.util.Random; import java.util.Scanner; import java.util.Set; public class Main { static final int GAME_SIZE = 40; //Disk sizes go from 0->39 // Produce a list of the first N prime numbers
[Code] ....
Results:
C:UsersSal_2>java Main Welcome to Towers of Toast!!! Type 'new' to start a new random puzzle Type 'load' to load a saved puzzle new [0, 2, 3, 4, 5, 6, 8, 10, 14, 19, 20, 25, 26, 28, 35, 38, 39] [7, 9, 11, 13, 15, 21, 22, 23, 27, 31, 32] [1, 12, 16, 17, 18, 24, 29, 30, 33, 34, 36, 37] | | XX | | XXX | | XXXX | | XXXXX | | XXXXXX | X XXXXXXXX XXXXXXX XXXXXXXXXXXX XXXXXXXXXX XXXXXXXXX XXXXXXXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXX XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXX XXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
The game is broken! We saved your game, though. Here are your save game numbers:
C:UsersSal_2>java Main Welcome to Towers of Toast!!! Type 'new' to start a new random puzzle Type 'load' to load a saved puzzle load Enter save number for pole 1: 3 Enter save number for pole 2: 1 Enter save number for pole 3: 11 Exception in thread "main" java.lang.RuntimeException: Not all disks accounted f or at Main.main(Main.java:100)
I have been struggling with this program for weeks. This program is supposed to take a user's inputted odd number and then print out all prime numbers lower than that number.
public class PrimeNumber { Scanner scan = new Scanner(System.in); int userNum; String neg;
would like to make .jar application, which will be able to sava data without using any database (Postgres...) but i dont know, what type of datastorage i should use to make the application portable. I just want to .jar file, which is capable works on any computer with java installed. Is there some option?
I'm doing project in area of "Cryptography and Network security". I'm having a file with binary Unicode (mean file contain Unicode value of corresponding data (text file)), want to divide that as blocks with the size of 144bits.
I am having problems with my code I have added the multiplication and division but they will not display also how can I correct any error when dividing by zero?
import java.awt.*; import java.awt.event.*; public class calculator2 extends java.applet.Applet implements ActionListener { TextField txtTotal = new TextField(""); Button button[] = new Button[10];
Here is the Butterfly sub division technique which refines the mesh of a STL file.I have to prepare a java code based on this technique, give the step by step procedure or algorithm for this.(files attached)
I was trying to execute the following program and the multiplication worked but the division didn't work.
import java.util.Scanner; public class BodyMassIndex { public static void main(String[] args) { // Prompt the user for weight and height // Create a scanner Scanner input = new Scanner (System.in); System.out.println("Please enter your weight in pounds"); int weight = input.nextInt(); System.out.println("Please enter your height in inches"); int height = input.nextInt (); double BMI = weight * (0.45359237)/ (height * 0.0254)*(height * 0.0254); // the weight * (0.45359237) executed but it wasn't divided by (height * 0.0254)*(height * 0.0254) System.out.println ("Your BMI is "+BMI);
Prompt for the project is "Write a program that will ask the user for a number of seconds and output the equivalent period of time in days, hours, minutes, and seconds.The program should:
-Use modulo division to calculate the number of days, hours, and minutes. -Use compound operators when making assignments. -Proper formatting and use of comments -Symbolic constants defined as the number of seconds in a minute, hour, and day.
For example: final int sec_in_min = 60;"
public class Mod1 { public static void main (String[] args) { int sec, min, hr, day; final int SEC_IN_MIN = 60; final int SEC_IN_HR = 60 * 60; final int SEC_IN_DAY = 60 * 60 * 24;
//checks wether an int is prime or not public static void main(String[] args) { int n = 17; boolean prime = true; if (!(n==2)) { for (int i = 2; i * i <= n; i++) { if (n % i == 0);
I am trying to list of prime number from n to m but my program give only one number
import java.io.PrintStream; import java.util.Scanner; public class Check05B { public static void main(String[] args) { Scanner input = new Scanner(System.in); PrintStream output = System.out; output.print("Enter a number to test: ");
public class printprimes2{ public static void main(String[] args){ for( int i = 1 ; i <=199 ; i++ ) //iterate 1 - 199; 2 is prime { for ( int j = 2 ; j < i ; j++ ) //iterate 2 - potential composite EXCLUSIVELY; every number can be divided by one and itself
[Code] ....
It doesn't print only prime numbers but all numbers that range from 0 to 199. What do you think I am doing wrong?
I am writing a program that checks if a number is prime or not. Code below.
for(int i = 2; i < P; i++){ if (P % i == 0) { System.out.println(P + " Can also be divided: " + i); return; } } System.out.println("Prime number.");
It works but, if a number is not a prime. I need to print out all the numbers that it can be divided with. For example if a number would be 8: it can also be divided with 1, 2, 4, 8.
