JAVA-12097: renamed algorithms-module to algorithms-modules

This commit is contained in:
sampadawagde
2022-05-20 22:07:32 +05:30
parent 3b028d36d0
commit a2afe2eed0
324 changed files with 31 additions and 20 deletions

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/target/
.settings/
.classpath
.project

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## Genetic Algorithms
This module contains articles about genetic algorithms.
### Relevant articles:
- [Introduction to Jenetics Library](https://www.baeldung.com/jenetics)
- [Ant Colony Optimization with a Java Example](https://www.baeldung.com/java-ant-colony-optimization)
- [Design a Genetic Algorithm in Java](https://www.baeldung.com/java-genetic-algorithm)
- [The Traveling Salesman Problem in Java](https://www.baeldung.com/java-simulated-annealing-for-traveling-salesman)

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<?xml version="1.0" encoding="UTF-8"?>
<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>
<artifactId>algorithms-genetic</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>algorithms-genetic</name>
<parent>
<groupId>com.baeldung</groupId>
<artifactId>algorithms-modules</artifactId>
<version>1.0.0-SNAPSHOT</version>
</parent>
<dependencies>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-math3</artifactId>
<version>${commons-math3.version}</version>
</dependency>
<dependency>
<groupId>commons-codec</groupId>
<artifactId>commons-codec</artifactId>
<version>${commons-codec.version}</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>${lombok.version}</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>io.jenetics</groupId>
<artifactId>jenetics</artifactId>
<version>${io.jenetics.version}</version>
</dependency>
</dependencies>
<properties>
<commons-math3.version>3.6.1</commons-math3.version>
<io.jenetics.version>3.7.0</io.jenetics.version>
<commons-codec.version>1.11</commons-codec.version>
</properties>
</project>

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package com.baeldung.algorithms;
import java.util.Scanner;
import com.baeldung.algorithms.ga.annealing.SimulatedAnnealing;
import com.baeldung.algorithms.ga.ant_colony.AntColonyOptimization;
import com.baeldung.algorithms.ga.binary.SimpleGeneticAlgorithm;
public class RunAlgorithm {
public static void main(String[] args) throws InstantiationException, IllegalAccessException {
Scanner in = new Scanner(System.in);
System.out.println("Run algorithm:");
System.out.println("1 - Simulated Annealing");
System.out.println("2 - Simple Genetic Algorithm");
System.out.println("3 - Ant Colony");
int decision = in.nextInt();
switch (decision) {
case 1:
System.out.println(
"Optimized distance for travel: " + SimulatedAnnealing.simulateAnnealing(10, 10000, 0.9995));
break;
case 2:
SimpleGeneticAlgorithm ga = new SimpleGeneticAlgorithm();
ga.runAlgorithm(50, "1011000100000100010000100000100111001000000100000100000000001111");
break;
case 3:
AntColonyOptimization antColony = new AntColonyOptimization(21);
antColony.startAntOptimization();
break;
default:
System.out.println("Unknown option");
break;
}
in.close();
}
}

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package com.baeldung.algorithms.ga.annealing;
import lombok.Data;
@Data
public class City {
private int x;
private int y;
public City() {
this.x = (int) (Math.random() * 500);
this.y = (int) (Math.random() * 500);
}
public double distanceToCity(City city) {
int x = Math.abs(getX() - city.getX());
int y = Math.abs(getY() - city.getY());
return Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2));
}
}

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package com.baeldung.algorithms.ga.annealing;
public class SimulatedAnnealing {
private static Travel travel = new Travel(10);
public static double simulateAnnealing(double startingTemperature, int numberOfIterations, double coolingRate) {
System.out.println("Starting SA with temperature: " + startingTemperature + ", # of iterations: " + numberOfIterations + " and colling rate: " + coolingRate);
double t = startingTemperature;
travel.generateInitialTravel();
double bestDistance = travel.getDistance();
System.out.println("Initial distance of travel: " + bestDistance);
Travel bestSolution = travel;
Travel currentSolution = bestSolution;
for (int i = 0; i < numberOfIterations; i++) {
if (t > 0.1) {
currentSolution.swapCities();
double currentDistance = currentSolution.getDistance();
if (currentDistance < bestDistance) {
bestDistance = currentDistance;
} else if (Math.exp((bestDistance - currentDistance) / t) < Math.random()) {
currentSolution.revertSwap();
}
t *= coolingRate;
} else {
continue;
}
if (i % 100 == 0) {
System.out.println("Iteration #" + i);
}
}
return bestDistance;
}
}

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package com.baeldung.algorithms.ga.annealing;
import java.util.ArrayList;
import java.util.Collections;
import lombok.Data;
@Data
public class Travel {
private ArrayList<City> travel = new ArrayList<>();
private ArrayList<City> previousTravel = new ArrayList<>();
public Travel(int numberOfCities) {
for (int i = 0; i < numberOfCities; i++) {
travel.add(new City());
}
}
public void generateInitialTravel() {
if (travel.isEmpty()) {
new Travel(10);
}
Collections.shuffle(travel);
}
public void swapCities() {
int a = generateRandomIndex();
int b = generateRandomIndex();
previousTravel = new ArrayList<>(travel);
City x = travel.get(a);
City y = travel.get(b);
travel.set(a, y);
travel.set(b, x);
}
public void revertSwap() {
travel = previousTravel;
}
private int generateRandomIndex() {
return (int) (Math.random() * travel.size());
}
public City getCity(int index) {
return travel.get(index);
}
public int getDistance() {
int distance = 0;
for (int index = 0; index < travel.size(); index++) {
City starting = getCity(index);
City destination;
if (index + 1 < travel.size()) {
destination = getCity(index + 1);
} else {
destination = getCity(0);
}
distance += starting.distanceToCity(destination);
}
return distance;
}
}

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package com.baeldung.algorithms.ga.ant_colony;
public class Ant {
protected int trailSize;
protected int trail[];
protected boolean visited[];
public Ant(int tourSize) {
this.trailSize = tourSize;
this.trail = new int[tourSize];
this.visited = new boolean[tourSize];
}
protected void visitCity(int currentIndex, int city) {
trail[currentIndex + 1] = city;
visited[city] = true;
}
protected boolean visited(int i) {
return visited[i];
}
protected double trailLength(double graph[][]) {
double length = graph[trail[trailSize - 1]][trail[0]];
for (int i = 0; i < trailSize - 1; i++) {
length += graph[trail[i]][trail[i + 1]];
}
return length;
}
protected void clear() {
for (int i = 0; i < trailSize; i++)
visited[i] = false;
}
}

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package com.baeldung.algorithms.ga.ant_colony;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.OptionalInt;
import java.util.Random;
import java.util.stream.IntStream;
public class AntColonyOptimization {
private double c = 1.0;
private double alpha = 1;
private double beta = 5;
private double evaporation = 0.5;
private double Q = 500;
private double antFactor = 0.8;
private double randomFactor = 0.01;
private int maxIterations = 1000;
private int numberOfCities;
private int numberOfAnts;
private double graph[][];
private double trails[][];
private List<Ant> ants = new ArrayList<>();
private Random random = new Random();
private double probabilities[];
private int currentIndex;
private int[] bestTourOrder;
private double bestTourLength;
public AntColonyOptimization(int noOfCities) {
graph = generateRandomMatrix(noOfCities);
numberOfCities = graph.length;
numberOfAnts = (int) (numberOfCities * antFactor);
trails = new double[numberOfCities][numberOfCities];
probabilities = new double[numberOfCities];
IntStream.range(0, numberOfAnts)
.forEach(i -> ants.add(new Ant(numberOfCities)));
}
/**
* Generate initial solution
*/
public double[][] generateRandomMatrix(int n) {
double[][] randomMatrix = new double[n][n];
IntStream.range(0, n)
.forEach(i -> IntStream.range(0, n)
.forEach(j -> randomMatrix[i][j] = Math.abs(random.nextInt(100) + 1)));
return randomMatrix;
}
/**
* Perform ant optimization
*/
public void startAntOptimization() {
IntStream.rangeClosed(1, 3)
.forEach(i -> {
System.out.println("Attempt #" + i);
solve();
});
}
/**
* Use this method to run the main logic
*/
public int[] solve() {
setupAnts();
clearTrails();
IntStream.range(0, maxIterations)
.forEach(i -> {
moveAnts();
updateTrails();
updateBest();
});
System.out.println("Best tour length: " + (bestTourLength - numberOfCities));
System.out.println("Best tour order: " + Arrays.toString(bestTourOrder));
return bestTourOrder.clone();
}
/**
* Prepare ants for the simulation
*/
private void setupAnts() {
IntStream.range(0, numberOfAnts)
.forEach(i -> {
ants.forEach(ant -> {
ant.clear();
ant.visitCity(-1, random.nextInt(numberOfCities));
});
});
currentIndex = 0;
}
/**
* At each iteration, move ants
*/
private void moveAnts() {
IntStream.range(currentIndex, numberOfCities - 1)
.forEach(i -> {
ants.forEach(ant -> ant.visitCity(currentIndex, selectNextCity(ant)));
currentIndex++;
});
}
/**
* Select next city for each ant
*/
private int selectNextCity(Ant ant) {
int t = random.nextInt(numberOfCities - currentIndex);
if (random.nextDouble() < randomFactor) {
OptionalInt cityIndex = IntStream.range(0, numberOfCities)
.filter(i -> i == t && !ant.visited(i))
.findFirst();
if (cityIndex.isPresent()) {
return cityIndex.getAsInt();
}
}
calculateProbabilities(ant);
double r = random.nextDouble();
double total = 0;
for (int i = 0; i < numberOfCities; i++) {
total += probabilities[i];
if (total >= r) {
return i;
}
}
throw new RuntimeException("There are no other cities");
}
/**
* Calculate the next city picks probabilites
*/
public void calculateProbabilities(Ant ant) {
int i = ant.trail[currentIndex];
double pheromone = 0.0;
for (int l = 0; l < numberOfCities; l++) {
if (!ant.visited(l)) {
pheromone += Math.pow(trails[i][l], alpha) * Math.pow(1.0 / graph[i][l], beta);
}
}
for (int j = 0; j < numberOfCities; j++) {
if (ant.visited(j)) {
probabilities[j] = 0.0;
} else {
double numerator = Math.pow(trails[i][j], alpha) * Math.pow(1.0 / graph[i][j], beta);
probabilities[j] = numerator / pheromone;
}
}
}
/**
* Update trails that ants used
*/
private void updateTrails() {
for (int i = 0; i < numberOfCities; i++) {
for (int j = 0; j < numberOfCities; j++) {
trails[i][j] *= evaporation;
}
}
for (Ant a : ants) {
double contribution = Q / a.trailLength(graph);
for (int i = 0; i < numberOfCities - 1; i++) {
trails[a.trail[i]][a.trail[i + 1]] += contribution;
}
trails[a.trail[numberOfCities - 1]][a.trail[0]] += contribution;
}
}
/**
* Update the best solution
*/
private void updateBest() {
if (bestTourOrder == null) {
bestTourOrder = ants.get(0).trail;
bestTourLength = ants.get(0)
.trailLength(graph);
}
for (Ant a : ants) {
if (a.trailLength(graph) < bestTourLength) {
bestTourLength = a.trailLength(graph);
bestTourOrder = a.trail.clone();
}
}
}
/**
* Clear trails after simulation
*/
private void clearTrails() {
IntStream.range(0, numberOfCities)
.forEach(i -> {
IntStream.range(0, numberOfCities)
.forEach(j -> trails[i][j] = c);
});
}
}

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package com.baeldung.algorithms.ga.binary;
import lombok.Data;
@Data
public class Individual {
protected int defaultGeneLength = 64;
private byte[] genes = new byte[defaultGeneLength];
private int fitness = 0;
public Individual() {
for (int i = 0; i < genes.length; i++) {
byte gene = (byte) Math.round(Math.random());
genes[i] = gene;
}
}
protected byte getSingleGene(int index) {
return genes[index];
}
protected void setSingleGene(int index, byte value) {
genes[index] = value;
fitness = 0;
}
public int getFitness() {
if (fitness == 0) {
fitness = SimpleGeneticAlgorithm.getFitness(this);
}
return fitness;
}
@Override
public String toString() {
String geneString = "";
for (int i = 0; i < genes.length; i++) {
geneString += getSingleGene(i);
}
return geneString;
}
}

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package com.baeldung.algorithms.ga.binary;
import java.util.ArrayList;
import java.util.List;
import lombok.Data;
@Data
public class Population {
private List<Individual> individuals;
public Population(int size, boolean createNew) {
individuals = new ArrayList<>();
if (createNew) {
createNewPopulation(size);
}
}
protected Individual getIndividual(int index) {
return individuals.get(index);
}
protected Individual getFittest() {
Individual fittest = individuals.get(0);
for (int i = 0; i < individuals.size(); i++) {
if (fittest.getFitness() <= getIndividual(i).getFitness()) {
fittest = getIndividual(i);
}
}
return fittest;
}
private void createNewPopulation(int size) {
for (int i = 0; i < size; i++) {
Individual newIndividual = new Individual();
individuals.add(i, newIndividual);
}
}
}

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package com.baeldung.algorithms.ga.binary;
import lombok.Data;
@Data
public class SimpleGeneticAlgorithm {
private static final double uniformRate = 0.5;
private static final double mutationRate = 0.025;
private static final int tournamentSize = 5;
private static final boolean elitism = true;
private static byte[] solution = new byte[64];
public boolean runAlgorithm(int populationSize, String solution) {
if (solution.length() != SimpleGeneticAlgorithm.solution.length) {
throw new RuntimeException("The solution needs to have " + SimpleGeneticAlgorithm.solution.length + " bytes");
}
setSolution(solution);
Population myPop = new Population(populationSize, true);
int generationCount = 1;
while (myPop.getFittest().getFitness() < getMaxFitness()) {
System.out.println("Generation: " + generationCount + " Correct genes found: " + myPop.getFittest().getFitness());
myPop = evolvePopulation(myPop);
generationCount++;
}
System.out.println("Solution found!");
System.out.println("Generation: " + generationCount);
System.out.println("Genes: ");
System.out.println(myPop.getFittest());
return true;
}
public Population evolvePopulation(Population pop) {
int elitismOffset;
Population newPopulation = new Population(pop.getIndividuals().size(), false);
if (elitism) {
newPopulation.getIndividuals().add(0, pop.getFittest());
elitismOffset = 1;
} else {
elitismOffset = 0;
}
for (int i = elitismOffset; i < pop.getIndividuals().size(); i++) {
Individual indiv1 = tournamentSelection(pop);
Individual indiv2 = tournamentSelection(pop);
Individual newIndiv = crossover(indiv1, indiv2);
newPopulation.getIndividuals().add(i, newIndiv);
}
for (int i = elitismOffset; i < newPopulation.getIndividuals().size(); i++) {
mutate(newPopulation.getIndividual(i));
}
return newPopulation;
}
private Individual crossover(Individual indiv1, Individual indiv2) {
Individual newSol = new Individual();
for (int i = 0; i < newSol.getDefaultGeneLength(); i++) {
if (Math.random() <= uniformRate) {
newSol.setSingleGene(i, indiv1.getSingleGene(i));
} else {
newSol.setSingleGene(i, indiv2.getSingleGene(i));
}
}
return newSol;
}
private void mutate(Individual indiv) {
for (int i = 0; i < indiv.getDefaultGeneLength(); i++) {
if (Math.random() <= mutationRate) {
byte gene = (byte) Math.round(Math.random());
indiv.setSingleGene(i, gene);
}
}
}
private Individual tournamentSelection(Population pop) {
Population tournament = new Population(tournamentSize, false);
for (int i = 0; i < tournamentSize; i++) {
int randomId = (int) (Math.random() * pop.getIndividuals().size());
tournament.getIndividuals().add(i, pop.getIndividual(randomId));
}
Individual fittest = tournament.getFittest();
return fittest;
}
protected static int getFitness(Individual individual) {
int fitness = 0;
for (int i = 0; i < individual.getDefaultGeneLength() && i < solution.length; i++) {
if (individual.getSingleGene(i) == solution[i]) {
fitness++;
}
}
return fitness;
}
protected int getMaxFitness() {
int maxFitness = solution.length;
return maxFitness;
}
protected void setSolution(String newSolution) {
solution = new byte[newSolution.length()];
for (int i = 0; i < newSolution.length(); i++) {
String character = newSolution.substring(i, i + 1);
if (character.contains("0") || character.contains("1")) {
solution[i] = Byte.parseByte(character);
} else {
solution[i] = 0;
}
}
}
}

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package com.baeldung.algorithms.ga.jenetics;
import static org.jenetics.engine.EvolutionResult.toBestPhenotype;
import static org.jenetics.engine.limit.bySteadyFitness;
import java.util.stream.Stream;
import org.jenetics.BitChromosome;
import org.jenetics.BitGene;
import org.jenetics.Mutator;
import org.jenetics.Phenotype;
import org.jenetics.RouletteWheelSelector;
import org.jenetics.SinglePointCrossover;
import org.jenetics.TournamentSelector;
import org.jenetics.engine.Engine;
import org.jenetics.engine.EvolutionStatistics;
//The main class.
public class Knapsack {
public static void main(String[] args) {
int nItems = 15;
double ksSize = nItems * 100.0 / 3.0;
KnapsackFF ff = new KnapsackFF(Stream.generate(KnapsackItem::random)
.limit(nItems)
.toArray(KnapsackItem[]::new), ksSize);
Engine<BitGene, Double> engine = Engine.builder(ff, BitChromosome.of(nItems, 0.5))
.populationSize(500)
.survivorsSelector(new TournamentSelector<>(5))
.offspringSelector(new RouletteWheelSelector<>())
.alterers(new Mutator<>(0.115), new SinglePointCrossover<>(0.16))
.build();
EvolutionStatistics<Double, ?> statistics = EvolutionStatistics.ofNumber();
Phenotype<BitGene, Double> best = engine.stream()
.limit(bySteadyFitness(7))
.limit(100)
.peek(statistics)
.collect(toBestPhenotype());
System.out.println(statistics);
System.out.println(best);
}
}

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package com.baeldung.algorithms.ga.jenetics;
import java.util.function.Function;
import org.jenetics.BitChromosome;
import org.jenetics.BitGene;
import org.jenetics.Genotype;
public class KnapsackFF implements Function<Genotype<BitGene>, Double> {
private KnapsackItem[] items;
private double size;
public KnapsackFF(KnapsackItem[] items, double size) {
this.items = items;
this.size = size;
}
@Override
public Double apply(Genotype<BitGene> gt) {
KnapsackItem sum = ((BitChromosome) gt.getChromosome()).ones()
.mapToObj(i -> items[i])
.collect(KnapsackItem.toSum());
return sum.size <= this.size ? sum.value : 0;
}
}

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package com.baeldung.algorithms.ga.jenetics;
import java.util.Random;
import java.util.stream.Collector;
import org.jenetics.util.RandomRegistry;
public class KnapsackItem {
public double size;
public double value;
public KnapsackItem(double size, double value) {
this.size = size;
this.value = value;
}
protected static KnapsackItem random() {
Random r = RandomRegistry.getRandom();
return new KnapsackItem(r.nextDouble() * 100, r.nextDouble() * 100);
}
protected static Collector<KnapsackItem, ?, KnapsackItem> toSum() {
return Collector.of(() -> new double[2], (a, b) -> {
a[0] += b.size;
a[1] += b.value;
} , (a, b) -> {
a[0] += b[0];
a[1] += b[1];
return a;
} , r -> new KnapsackItem(r[0], r[1]));
}
}

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package com.baeldung.algorithms.ga.jenetics;
import org.jenetics.BitChromosome;
import org.jenetics.BitGene;
import org.jenetics.Genotype;
import org.jenetics.engine.Engine;
import org.jenetics.engine.EvolutionResult;
import org.jenetics.util.Factory;
public class SimpleGeneticAlgorithm {
private static Integer eval(Genotype<BitGene> gt) {
return gt.getChromosome()
.as(BitChromosome.class)
.bitCount();
}
public static void main(String[] args) {
Factory<Genotype<BitGene>> gtf = Genotype.of(BitChromosome.of(10, 0.5));
System.out.println("Before the evolution:\n" + gtf);
Engine<BitGene, Integer> engine = Engine.builder(SimpleGeneticAlgorithm::eval, gtf)
.build();
Genotype<BitGene> result = engine.stream()
.limit(500)
.collect(EvolutionResult.toBestGenotype());
System.out.println("After the evolution:\n" + result);
}
}

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package com.baeldung.algorithms.ga.jenetics;
import static java.util.Objects.requireNonNull;
import java.util.function.Function;
import java.util.stream.Collectors;
import org.jenetics.BitGene;
import org.jenetics.engine.Codec;
import org.jenetics.engine.Engine;
import org.jenetics.engine.EvolutionResult;
import org.jenetics.engine.Problem;
import org.jenetics.engine.codecs;
import org.jenetics.util.ISeq;
public class SpringsteenProblem implements Problem<ISeq<SpringsteenRecord>, BitGene, Double> {
private ISeq<SpringsteenRecord> records;
private double maxPricePerUniqueSong;
public SpringsteenProblem(ISeq<SpringsteenRecord> records, double maxPricePerUniqueSong) {
this.records = requireNonNull(records);
this.maxPricePerUniqueSong = maxPricePerUniqueSong;
}
@Override
public Function<ISeq<SpringsteenRecord>, Double> fitness() {
return SpringsteenRecords -> {
double cost = SpringsteenRecords.stream()
.mapToDouble(r -> r.price)
.sum();
int uniqueSongCount = SpringsteenRecords.stream()
.flatMap(r -> r.songs.stream())
.collect(Collectors.toSet())
.size();
double pricePerUniqueSong = cost / uniqueSongCount;
return pricePerUniqueSong <= maxPricePerUniqueSong ? uniqueSongCount : 0.0;
};
}
@Override
public Codec<ISeq<SpringsteenRecord>, BitGene> codec() {
return codecs.ofSubSet(records);
}
public static void main(String[] args) {
double maxPricePerUniqueSong = 2.5;
SpringsteenProblem springsteen = new SpringsteenProblem(
ISeq.of(new SpringsteenRecord("SpringsteenRecord1", 25, ISeq.of("Song1", "Song2", "Song3", "Song4", "Song5", "Song6")), new SpringsteenRecord("SpringsteenRecord2", 15, ISeq.of("Song2", "Song3", "Song4", "Song5", "Song6", "Song7")),
new SpringsteenRecord("SpringsteenRecord3", 35, ISeq.of("Song5", "Song6", "Song7", "Song8", "Song9", "Song10")), new SpringsteenRecord("SpringsteenRecord4", 17, ISeq.of("Song9", "Song10", "Song12", "Song4", "Song13", "Song14")),
new SpringsteenRecord("SpringsteenRecord5", 29, ISeq.of("Song1", "Song2", "Song13", "Song14", "Song15", "Song16")), new SpringsteenRecord("SpringsteenRecord6", 5, ISeq.of("Song18", "Song20", "Song30", "Song40"))),
maxPricePerUniqueSong);
Engine<BitGene, Double> engine = Engine.builder(springsteen)
.build();
ISeq<SpringsteenRecord> result = springsteen.codec()
.decoder()
.apply(engine.stream()
.limit(10)
.collect(EvolutionResult.toBestGenotype()));
double cost = result.stream()
.mapToDouble(r -> r.price)
.sum();
int uniqueSongCount = result.stream()
.flatMap(r -> r.songs.stream())
.collect(Collectors.toSet())
.size();
double pricePerUniqueSong = cost / uniqueSongCount;
System.out.println("Overall cost: " + cost);
System.out.println("Unique songs: " + uniqueSongCount);
System.out.println("Cost per song: " + pricePerUniqueSong);
System.out.println("Records: " + result.map(r -> r.name)
.toString(", "));
}
}

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package com.baeldung.algorithms.ga.jenetics;
import static java.util.Objects.requireNonNull;
import org.jenetics.util.ISeq;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@NoArgsConstructor
public class SpringsteenRecord {
String name;
double price;
ISeq<String> songs;
public SpringsteenRecord(String name, double price, ISeq<String> songs) {
this.name = requireNonNull(name);
this.price = price;
this.songs = requireNonNull(songs);
}
}

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package com.baeldung.algorithms.ga.jenetics;
import static java.util.Objects.requireNonNull;
import java.util.Random;
import java.util.function.Function;
import org.jenetics.EnumGene;
import org.jenetics.Mutator;
import org.jenetics.PartiallyMatchedCrossover;
import org.jenetics.Phenotype;
import org.jenetics.engine.Codec;
import org.jenetics.engine.Engine;
import org.jenetics.engine.EvolutionResult;
import org.jenetics.engine.Problem;
import org.jenetics.engine.codecs;
import org.jenetics.engine.limit;
import org.jenetics.util.ISeq;
import org.jenetics.util.LCG64ShiftRandom;
public class SubsetSum implements Problem<ISeq<Integer>, EnumGene<Integer>, Integer> {
private ISeq<Integer> basicSet;
private int size;
public SubsetSum(ISeq<Integer> basicSet, int size) {
this.basicSet = requireNonNull(basicSet);
this.size = size;
}
@Override
public Function<ISeq<Integer>, Integer> fitness() {
return subset -> Math.abs(subset.stream()
.mapToInt(Integer::intValue)
.sum());
}
@Override
public Codec<ISeq<Integer>, EnumGene<Integer>> codec() {
return codecs.ofSubSet(basicSet, size);
}
public static SubsetSum of(int n, int k, Random random) {
return new SubsetSum(random.doubles()
.limit(n)
.mapToObj(d -> (int) ((d - 0.5) * n))
.collect(ISeq.toISeq()), k);
}
public static void main(String[] args) {
SubsetSum problem = of(500, 15, new LCG64ShiftRandom(101010));
Engine<EnumGene<Integer>, Integer> engine = Engine.builder(problem)
.minimizing()
.maximalPhenotypeAge(5)
.alterers(new PartiallyMatchedCrossover<>(0.4), new Mutator<>(0.3))
.build();
Phenotype<EnumGene<Integer>, Integer> result = engine.stream()
.limit(limit.bySteadyFitness(55))
.collect(EvolutionResult.toBestPhenotype());
System.out.print(result);
}
}

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package com.baeldung.algorithms.ga.jenetics;
import static java.lang.Math.PI;
import static java.lang.Math.abs;
import static java.lang.Math.sin;
import static org.jenetics.engine.EvolutionResult.toBestPhenotype;
import static org.jenetics.engine.limit.bySteadyFitness;
import java.util.stream.IntStream;
import org.jenetics.EnumGene;
import org.jenetics.Optimize;
import org.jenetics.PartiallyMatchedCrossover;
import org.jenetics.Phenotype;
import org.jenetics.SwapMutator;
import org.jenetics.engine.Engine;
import org.jenetics.engine.EvolutionStatistics;
import org.jenetics.engine.codecs;
public class TravelingSalesman {
private static final int STOPS = 50;
private static final double[][] ADJACENCE = matrix(STOPS);
private static double[][] matrix(int stops) {
final double radius = 100.0;
double[][] matrix = new double[stops][stops];
for (int i = 0; i < stops; ++i) {
for (int j = 0; j < stops; ++j) {
matrix[i][j] = chord(stops, abs(i - j), radius);
}
}
return matrix;
}
private static double chord(int stops, int i, double r) {
return 2.0 * r * abs(sin(PI * i / stops));
}
private static double dist(final int[] path) {
return IntStream.range(0, STOPS)
.mapToDouble(i -> ADJACENCE[path[i]][path[(i + 1) % STOPS]])
.sum();
}
public static void main(String[] args) {
final Engine<EnumGene<Integer>, Double> engine = Engine.builder(TravelingSalesman::dist, codecs.ofPermutation(STOPS))
.optimize(Optimize.MINIMUM)
.maximalPhenotypeAge(11)
.populationSize(500)
.alterers(new SwapMutator<>(0.2), new PartiallyMatchedCrossover<>(0.35))
.build();
final EvolutionStatistics<Double, ?> statistics = EvolutionStatistics.ofNumber();
final Phenotype<EnumGene<Integer>, Double> best = engine.stream()
.limit(bySteadyFitness(15))
.limit(250)
.peek(statistics)
.collect(toBestPhenotype());
System.out.println(statistics);
System.out.println(best);
}
}

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<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
</pattern>
</encoder>
</appender>
<root level="INFO">
<appender-ref ref="STDOUT" />
</root>
</configuration>

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package com.baeldung.algorithms;
import org.junit.Assert;
import org.junit.Test;
import com.baeldung.algorithms.ga.ant_colony.AntColonyOptimization;
public class AntColonyOptimizationLongRunningUnitTest {
@Test
public void testGenerateRandomMatrix() {
AntColonyOptimization antTSP = new AntColonyOptimization(5);
Assert.assertNotNull(antTSP.generateRandomMatrix(5));
}
@Test
public void testStartAntOptimization() {
AntColonyOptimization antTSP = new AntColonyOptimization(5);
Assert.assertNotNull(antTSP.solve());
}
}

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package com.baeldung.algorithms;
import org.junit.Assert;
import org.junit.Test;
import com.baeldung.algorithms.ga.binary.SimpleGeneticAlgorithm;
public class BinaryGeneticAlgorithmLongRunningUnitTest {
@Test
public void testGA() {
SimpleGeneticAlgorithm ga = new SimpleGeneticAlgorithm();
Assert.assertTrue(ga.runAlgorithm(50, "1011000100000100010000100000100111001000000100000100000000001111"));
}
}

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package com.baeldung.algorithms;
import org.junit.Assert;
import org.junit.Test;
import com.baeldung.algorithms.ga.annealing.SimulatedAnnealing;
public class SimulatedAnnealingLongRunningUnitTest {
@Test
public void testSimulateAnnealing() {
Assert.assertTrue(SimulatedAnnealing.simulateAnnealing(10, 1000, 0.9) > 0);
}
}