LuxXx

package euler;

import java.util.Arrays;

public class SameDigits {
	public static String sort(String s) {
		char[] array = s.toCharArray();
		Arrays.sort(array);
		return new String(array);
	}

LuxXx

public class Test {
	public static void main(String[] args) {
		System.out.println(concat(12, 34));
	}
	public static int concat(int a, int b) {
		if (b == 0) return a*10;
		return a*pow(10,len(b)) + b;
	}
	public static int pow (int a, int b) {
		if (b == 0) return 1;

LuxXx

public class Champernowne {
	
	private static String num = null;
	
	public static void main(String[] args) {
		StringBuilder sb = new StringBuilder();
		
		for (int i = 0; i < 1_000_000; i++) {
			sb.append(String.valueOf(i));
			if (i == 0) sb.append('.');

LuxXx

package euler;

public class ChainMember {
	private int n;
	
	// we use a -1 as n to indicate that this is a 89 to differ them from 0 or 1
	private static final ChainMember EIGHTYNINE = new ChainMember(-1);
	
	public ChainMember(int n) {
		this.n = n;

LuxXx

package dailyprogrammer;

import java.util.Arrays;


/**
 * https://www.reddit.com/r/dailyprogrammer/comments/67q3s6/20170426_challenge_312_intermediate_next_largest/
 * @author David
 *
 */

LuxXx

import java.util.Comparator;
import java.util.PriorityQueue;

public class Comp {
	public static void main(String[] args) {
		PriorityQueue<Integer> q = new PriorityQueue<>(new Comparator<Integer>() {
			@Override
			public int compare(Integer o1, Integer o2) {
				return sig(o1 - o2);

LuxXx

public class IsEven {
	public static boolean isEven_bit(int i) {
		return (i & 1) == 0;
	}
	public static boolean isEven_mod(int i) {
		return i % 2 == 0;
	}
	public static void main(String[] args) {
		isEven_bit(2);
		isEven_mod(2);

LuxXx

public class Fraction {
	
	public static final Fraction ONE = new Fraction(1);
	public static final Fraction TWO = new Fraction(2);
	public static final Fraction TEN = new Fraction(10);
	
	private long num;
	private long denom;
	

LuxXx

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;

import javax.swing.JOptionPane;

public final class Logger {
	

LuxXx

/**
 * @author David
 * 
 * When I took an introductory course in mathematics, the lecturer introduced the natural numbers
 * using a set of axioms called the peano axioms.
 * I wondered if it would be possible to create a Java class that represents the integers without
 * using any primitive type such as int, double, byte, boolean, etc.
 * The class should be able to perform the operations + and *.
 * I also created the relation ==, <, >, <=, >= to define an order.
 *