KryptoAufgabe1

KryptoException.java

package fh.krypto.Aufgabe1;

public class KryptoMathException extends Exception{

	public KryptoMathException(String string) {
		super(string);
	}

}

KryptoMath.java

package fh.krypto.Aufgabe1;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Stack;
import java.util.stream.IntStream;

import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.Multimap;
import com.google.common.collect.MultimapBuilder;
import com.google.common.collect.Multimaps;

/**
 * 
 * @author sven
 *
 */
public class KryptoMath 
{
	private static List<String> linearCombinations = new ArrayList<String>();
	private static StringBuilder builder = new StringBuilder();
	private static Stack<int[]>combination = new Stack<>(); 
	
	
    public static int getLeastCommonFactor(final int a,final int b) throws KryptoMathException {
    	int rest =0;
    	int bufferA=a;
    	int buffer=0;
    	if(b==0) throw new KryptoMathException("Kann nicht durch 0 teilen");
    	
    	rest = b;
    	int[] blah = new int[3];
    	do {
    		
    		buffer=rest;
    		rest=getRest(bufferA, rest);
    		if(rest==1){
				rest=0;
				buffer=-1;
			}else{
				builder.append('\n');
				bufferA=buffer;
			}
			
		} while (rest!=0);
    	if(buffer!=-1){
    		addCombination(bufferA);
    	}
    	
		return buffer;
	}
    
    private static int getRest(int start, int divisor){
    	int[] numbers = new int[4];
    	int times=0;
    	times=0;
		times = start/divisor;
		if((start-(divisor*times)==0))return 0;
		numbers[0]=start;
		numbers[1]=times;
		numbers[2]=divisor;
		numbers[3]=(start-(divisor*times));
		combination.push(numbers);
		builder.append(start)
		.append('=')
		.append(times)
		.append('*')
		.append(divisor)
		.append('+')
		.append((start-(divisor*times)));
		return (start-(divisor*times));
    }
    
    private static void addCombination(int d){
    	builder.append(d)
    	.append('=');
    	int[] buffer;
    	int[] buffer2;
    	while(!combination.isEmpty()&&combination.size()>1){
    		buffer=combination.pop();
    		buffer2=combination.peek();
    		builder.append(buffer[0])
    		.append('-')
    		.append(buffer[1])
    		.append('*').append('(')
    		.append(buffer2[0]).append('-')
    		.append(buffer2[1])
    		.append('*')
    		.append(buffer[0]).append(')').append('=')
    		.append('-')
    		.append(buffer[1]).append('*')
    		.append(buffer2[0])
    		.append('+').append('(')
    		.append('1').append('+')
    		.append(buffer[1])
    		.append('*')
    		.append(buffer2[1]).append(')')
    		.append('*')
    		.append(buffer[0]);
    		if(combination.size()!=1){
    			builder.append('=');
    		}
    	}
    }
    
    
    


	/**
	 * @return the linearCombinations
	 */
	public static String getLinearCombinations() {
		return builder.toString();
	}
    
	
    
    
    
    
    
    
}

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>fh.krypto</groupId>
	<artifactId>Aufgabe1</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>Aufgabe1</name>
	<url>http://maven.apache.org</url>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
	</properties>

	<dependencies>
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.12</version>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>com.google.guava</groupId>
			<artifactId>guava</artifactId>
			<version>21.0</version>
		</dependency>
	</dependencies>
</project>

TestKrypto.java

package fh.krypto.Aufgabe1;

import org.junit.Test;

/**
 * Unit test for simple App.
 */
public class AppTest 
    
{
	@Test
    public void testLeastCommonFactorize() {
		try {
			int a = KryptoMath.getLeastCommonFactor(2406, 654);
			System.out.println(a);
			System.out.println(KryptoMath.getLinearCombinations());
		} catch (KryptoMathException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}