initial commit

.gitignore

+### IntelliJ IDEA ###
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store

src/Bot.java

+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.net.Socket;
+import java.net.InetSocketAddress;
+
+public abstract class Bot {
+
+    // Ein Bot ist ein Programm, das sich mit einem Server verbindet und
+    // mit diesem kommuniziert. Der Server sendet dem Bot eine Zeichenkette,
+    // die das Spielfeld repräsentiert. Der Bot sendet dem Server ein Zeichen,
+    // das die nächste Bewegung des Bots repräsentiert.
+
+
+    private final String host;  // Hostname oder IP-Adresse des Servers
+    private final int port;     // Port des Servers
+
+    protected Bot(String[] args) {
+        host = args.length > 0 ? args[0] : "localhost";
+        port = args.length > 1 ? Integer.parseInt(args[1]) : 63187;
+    }
+
+    // Diese Methode stellt die Verbindung zum Server her und startet die
+    // Kommunikation mit dem Server. Die Methode wird von der main-Methode
+    // aufgerufen.
+    protected void run() {
+        try (Socket socket = new Socket()) {
+            socket.connect(new InetSocketAddress(host, port));
+            OutputStream out = socket.getOutputStream();
+            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
+            View view = new View();
+            while (true) {
+                view.read(in);
+                view.print();
+                try {
+                    char ch = nextMove(view);
+                    out.write(ch);
+                }
+                catch (Exception e) { break; }
+            }
+            socket.close();
+        } catch (IOException e) {
+            System.err.println("Error: " + e.getMessage());
+        }
+    }
+
+    // Diese Methode ermittelt den nächsten Zug des Bots. Sie wird von der
+    // run-Methode aufgerufen, nachdem der Server das Spielfeld gesendet hat.
+    // Subklassen müssen diese Methode implementieren.
+    abstract protected char nextMove(View view) throws Exception;
+
+    // Diese Klasse repräsentiert das Spielfeld. Sie wird von der run-Methode
+    // verwendet, um das Spielfeld zu lesen und auszugeben.
+    // Subklassen können diese Klasse verwenden, um das Spielfeld zu analysieren.
+    public static class View {
+        protected String data;
+        protected int width;
+
+        // Diese Methode liest das Spielfeld vom Server.
+        private void read(BufferedReader in) throws IOException {
+            StringBuilder sb = new StringBuilder();
+            data = in.readLine();
+            if (data == null) {
+                return;
+            }
+            sb.append(data);
+            width = data.length();
+            for (int i = 1; i < width; ++i) {
+                sb.append(in.readLine());
+            }
+            data = sb.toString();
+        }
+
+        // Diese Methode gibt das Spielfeld aus.
+        protected void print() {
+            if (data == null || width < 1) {
+                return;
+            }
+            for (int i = 0, len = data.length(); i < len; i += width) {
+                System.out.println(data.substring(i, i + width));
+            }
+        }
+    }
+}

src/CollectBot.java

+import java.util.Stack;
+
+public class CollectBot extends SmartBot {
+
+    private int maxNumberOfTilesToMove = 15;
+
+    private int tilesMoved;
+
+    private char directionBias;
+
+    private final Stack<Character> moves;
+
+    protected CollectBot(String[] args) {
+        super(args);
+        tilesMoved = 0;
+        directionBias = LEFT;
+        moves = new Stack<Character>();
+    }
+
+    public static void main(String[] args) {
+        Bot bot = new CollectBot(args);
+        bot.run();
+    }
+
+    @Override
+    protected char nextMove(View view) throws Exception {
+        char move = '^';
+
+        // Search larger areas after a time
+        if (moves.size() != 0 && moves.size() % 100 == 0 && maxNumberOfTilesToMove <=30) {
+            maxNumberOfTilesToMove += 5;
+        }
+
+        // Look for Gems
+        int turn = scanView(view);
+        if (turn == 3) {
+            tilesMoved++;
+            // Change up direction after not encountering anything for a while
+            if (tilesMoved >= maxNumberOfTilesToMove) {
+                tilesMoved = 0;
+                move = switchBias(true);
+            }
+        } else {
+            tilesMoved = 0;
+            move = switch (turn) {
+                case -1 -> LEFT;
+                case 0 -> FORWARD;
+                case 1 -> RIGHT;
+                default -> move;
+            };
+        }
+        moves.push(move);
+        return move;
+    }
+
+    /***
+     * This Method can be either used to detect potential spiral collision paths or to periodically change the direction bias
+     * @param numberOfTurns The number of turns that should be equal
+     * @return true, if the last n turns were equal in the given distance covered
+     */
+    private boolean evaluateNumberOfEqualTurns(int numberOfTurns) {
+        if (this.moves.isEmpty() || this.moves.size() < 3) {
+            return false;
+        }
+        Stack<Character> moves = (Stack<Character>) this.moves.clone();
+        int numberOfEqualTurns = 0;
+        int distanceCovered = 0;
+        char directionToCompare = '#';
+        while (numberOfEqualTurns <= numberOfTurns && !moves.isEmpty()) {
+            char lastMove = moves.pop();
+            if (lastMove == FORWARD) {
+                distanceCovered++;
+                continue;
+            }
+
+            if (numberOfEqualTurns == 0) {
+                numberOfEqualTurns++;
+                directionToCompare = lastMove;
+            } else {
+                if (lastMove != directionToCompare) {
+                    return false;
+                }
+                numberOfEqualTurns++;
+            }
+        }
+        return numberOfEqualTurns == 3;
+    }
+
+    /***
+     * Changes up the direction bias every two turns which achieves a rough zig-zag pattern
+     * @return the next direction bias
+     */
+    protected char switchBias(boolean forcedSwitch) {
+        if(!evaluateNumberOfEqualTurns(2) && !forcedSwitch) {
+            return directionBias;
+        }
+        directionBias = switch (directionBias) {
+            case LEFT -> {
+                directionBias = RIGHT;
+                yield RIGHT;
+            }
+            case RIGHT -> {
+                directionBias = LEFT;
+                yield LEFT;
+            }
+            default -> directionBias;
+        };
+        return directionBias;
+    }
+
+    protected char switchBias() {
+        return switchBias(false);
+    }
+
+    protected int scanView(View view) {
+        if (view.data.contains("@")) {
+            int stone = view.data.indexOf("@") + 1;
+
+            // Check Front:
+            switch (stone) {
+                case 3, 8:
+                    return 0;
+            }
+
+            // If possible, prefer direction Bias
+            if (directionBias == LEFT) {
+                switch (stone) {
+                    case 11, 12: return -1; // left
+                    case 14, 15: return  1; // right
+                }
+            } else {
+                switch (stone) {
+                    case 14, 15: return  1; // right
+                    case 11, 12: return -1; // left
+                }
+            }
+        }
+        return 3;
+    }
+}

src/DummyBot.java

+import java.util.Random;
+
+public class DummyBot extends SmartBot {
+
+    Random random;
+
+    protected DummyBot(String[] args) {
+        super(args);
+        random = new Random();
+    }
+
+    public static void main(String[] args) {
+        Bot bot = new DummyBot(args);
+        bot.run();
+    }
+
+    @Override
+    protected char nextMove(View view) throws Exception {
+        int move = random.nextInt(0, 7);
+        return switch (move) {
+            case 1,2,3 -> FORWARD;
+            case 4 -> LEFT;
+            case 5 -> RIGHT;
+            case 6 -> SHOOT;
+            default -> 0;
+        };
+    }
+
+}

src/EscapeBot.java

+public class EscapeBot extends Bot {
+
+    int unitsMoved;
+
+    int unitsToMove;
+
+    int timesTurned;
+
+    protected EscapeBot(String[] args) {
+        super(args);
+        unitsMoved = 0;
+        unitsToMove = 5;
+        timesTurned = 0;
+    }
+
+    public static void main(String[] args) {
+        Bot bot = new EscapeBot(args);
+        bot.run();
+    }
+
+    @Override
+    protected char nextMove(View view) throws Exception {
+        //boolean found = false;
+
+        if (unitsMoved % 5 == 0) {
+            char c = checkView(view);
+            switch (c) {
+                case '0': break;
+                case '1': throw new Exception("found!");
+                default: return c;
+            }
+        }
+
+        if (unitsMoved < unitsToMove) {
+            unitsMoved++;
+            return '^';
+        } else if (unitsMoved == unitsToMove) {
+            unitsMoved = 0;
+            timesTurned++;
+
+            if (timesTurned % 2 == 0) {
+                unitsToMove += 5;
+            }
+            return '>';
+        }
+
+        throw new Exception();
+    }
+
+    private char checkView(View view) {
+        if (view.data.contains("o")) {
+            int spaceship = view.data.indexOf("o") + 1;
+            if (spaceship == 13) {
+                return '1';
+            } else if (spaceship <= 10) {
+                return '^';
+            } else if (spaceship >= 15) {
+                return 'v';
+            } else if (spaceship%5 < 3) {
+                return '<';
+            } else if (spaceship%5 > 3) {
+                return '>';
+            }
+        }
+        return '0';
+    }
+}

src/RumbleBot.java

+import java.util.Random;
+
+public class RumbleBot extends SmartBot {
+
+    private int tilesToMove;
+
+    private int escapeMove;
+
+    private final Random random;
+
+    private final int[] leftVectorIndizes = new int[] {36,37,38,39};
+    private final int[] rightVectorIndizes = new int[] {23,24,25,26};
+    private final int[] frontVectorIndizes = new int[] {4,13,22,31};
+
+    protected RumbleBot(String[] args) {
+        super(args);
+        this.random = new Random();
+        this.escapeMove = 0;
+        this.tilesToMove = random.nextInt(5, 15);
+    }
+
+    public static void main(String[] args) {
+        Bot bot = new RumbleBot(args);
+        bot.run();
+    }
+
+    @Override
+    protected char nextMove(View view) throws Exception {
+        char move = FORWARD;
+
+//        if (tilesToMove >= tilesMoved) {
+//            tilesMoved = 0;
+//            tilesToMove = random.nextInt(5, 15);
+//            move = directionBias;
+//        }
+
+        if (escapeMove != 0) {
+            escapeMove--;
+            return FORWARD;
+        }
+
+        // Check for enemies
+        Enemy enemy = evaluateEnemy(view);
+        if (enemy != null) {
+            move = calculateOptimalMove(view, enemy);
+            escapeMove = 3;
+        }
+
+        if (directionBlocked(view,FORWARD)) {
+            if (directionBlocked(view,RIGHT)) {
+                move = LEFT;
+            } else {
+                move = RIGHT;
+            }
+        }
+
+        return move;
+    }
+
+    private Enemy evaluateEnemy(View view) {
+        int enemyPos;
+        if (view.data.contains("^")) {
+            enemyPos = view.data.indexOf('^');
+        } else if (view.data.contains("v")) {
+            enemyPos = view.data.indexOf('v');
+        } else if (view.data.contains("<")) {
+            enemyPos = view.data.indexOf('<');
+        } else if (view.data.contains(">")) {
+            enemyPos = view.data.indexOf('>');
+        } else {
+            return null;
+        }
+        return new Enemy(enemyPos + 1, view.data.charAt(enemyPos));
+    }
+
+    public boolean directionBlocked(View view, char direction) {
+        if (direction == FORWARD) {
+            for (int i = 4; i < 32; i+=9) {
+                if (view.data.charAt(i) == 'X') {
+                    return true;
+                }
+            }
+        } else if (direction == LEFT) {
+            for (int i = 36; i < 40; i++) {
+                if (view.data.charAt(i) == 'X') {
+                    return true;
+                }
+            }
+        } else if (direction == RIGHT) {
+            for (int i = 41; i < 45; i++) {
+                if (view.data.charAt(i) == 'X') {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    private char calculateOptimalMove(View view, Enemy enemy) {
+        int pos = enemy.position;
+        char dir = enemy.direction;
+
+
+        // Top Sector
+        if (pos <= 18) {
+            // Left Half
+            if (pos % 9 < 5) {
+                return !directionBlocked(view,RIGHT) ? RIGHT : SHOOT;
+            }
+
+            // Right Half
+            else if (pos % 9 > 5) {
+                return !directionBlocked(view,LEFT) ? LEFT : SHOOT;
+            }
+            // Center
+            else {
+                return SHOOT;
+            }
+        }
+
+        // Bottom Sector
+        if (pos >= 24) {
+            // Left or Right Half
+            if (pos % 9 != 5) {
+                return !directionBlocked(view,FORWARD) ? FORWARD : randomDirection(view);
+            }
+            // Center
+            else {
+                return randomDirection(view);
+            }
+        }
+
+        // Left or Right
+        return randomDirection(view);
+    }
+
+    private char randomDirection(View view) {
+        int rand = random.nextInt(0, 1);
+        char dir = rand == 0 ? '<' : '>';
+        return !directionBlocked(view,dir) ? dir : flipDirection(dir);
+    }
+
+    private char flipDirection(char direction) {
+        return switch (direction) {
+            case RIGHT -> LEFT;
+            case LEFT -> RIGHT;
+            case FORWARD -> BACKWARD;
+            default -> FORWARD;
+        };
+    }
+
+    private static class Enemy {
+        final int position;
+        final char direction;
+
+        public Enemy(int position, char direction) {
+            this.position = position;
+            this.direction = direction;
+        }
+
+    }
+
+}

src/SmartBot.java

+import java.util.Stack;
+
+public abstract class SmartBot extends Bot {
+
+    protected static final char FORWARD = '^';
+    protected static final char BACKWARD = 'v';
+    protected static final char LEFT = '<';
+    protected static final char RIGHT = '>';
+    protected static final char SHOOT = 'f';
+
+    protected int tilesMoved;
+
+    protected final Stack<Character> moves;
+
+
+    protected SmartBot(String[] args) {
+        super(args);
+        this.tilesMoved = 0;
+        this.moves = new Stack<>();
+    }
+
+    @Override
+    protected char nextMove(View view) throws Exception {
+        return 0;
+    }
+
+
+}

src/SnakeBot.java

+import java.util.Stack;
+
+public class SnakeBot extends SmartBot {
+
+    private int maxNumberOfTilesToMove = 15;
+
+    private int tilesMoved;
+
+    private int tailLength;
+
+    private int escapeSequence;
+
+    private char directionBias;
+
+    private final Stack<Character> moves;
+
+    protected SnakeBot(String[] args) {
+        super(args);
+        tilesMoved = 0;
+        tailLength = 0;
+        escapeSequence = 0;
+        directionBias = LEFT;
+        moves = new Stack<Character>();
+    }
+
+    public static void main(String[] args) {
+        Bot bot = new SnakeBot(args);
+        bot.run();
+    }
+
+    @Override
+    protected char nextMove(View view) throws Exception {
+        char move = '^';
+
+        // Avoid potential spiral paths
+        if (evaluateNumberOfEqualTurns(3, tailLength)) {
+            moves.push(switchBias());
+            System.out.println("Potential Spiral detected. Next Move: " + directionBias);
+            escapeSequence = 2;
+            return directionBias;
+        }
+
+        // Way must be free
+        if (!checkFrontCollisions(view)) {
+            escapeSequence = 1;
+            moves.push(switchBias());
+            System.out.println("Collision ahead. Next Move: " + directionBias);
+
+            return directionBias;
+        }
+
+        // Escape after potential collision or spiral turn loops
+        if (escapeSequence != 0) {
+            switch (escapeSequence) {
+                case 1:
+                    escapeSequence = 0;
+                    moves.push(FORWARD);
+                    return FORWARD;
+                case 2:
+                    escapeSequence = 1;
+                    moves.push(switchBias());
+                    return directionBias;
+            }
+        }
+
+        // Search larger areas after a time
+        if (moves.size() != 0 && moves.size() % 100 == 0 && maxNumberOfTilesToMove <=30) {
+            maxNumberOfTilesToMove += 5;
+        }
+
+        // Look for Gems
+        int turn = scanView(view);
+        if (turn == 3) {
+            tilesMoved++;
+            // Change up direction after not encountering anything for a while
+            if (tilesMoved >= maxNumberOfTilesToMove) {
+                tilesMoved = 0;
+                move = switchBias(true);
+            }
+        } else {
+            tilesMoved = 0;
+            move = switch (turn) {
+                case -1 -> LEFT;
+                case 0 -> FORWARD;
+                case 1 -> RIGHT;
+                default -> move;
+            };
+        }
+        moves.push(move);
+        return move;
+    }
+
+    /***
+     * This Method can be either used to detect potential spiral collision paths or to periodically change the direction bias
+     * @param numberOfTurns The number of turns that should be equal
+     * @param maxDepth The distance in wich the turns must have occurred to be considered
+     * @return true, if the last n turns were equal in the given distance covered
+     */
+    private boolean evaluateNumberOfEqualTurns(int numberOfTurns, int maxDepth) {
+        if (this.moves.isEmpty() || this.moves.size() < 3) {
+            return false;
+        }
+        Stack<Character> moves = (Stack<Character>) this.moves.clone();
+        int numberOfEqualTurns = 0;
+        int distanceCovered = 0;
+        char directionToCompare = '#';
+        while (numberOfEqualTurns <= numberOfTurns && distanceCovered <= maxDepth && !moves.isEmpty()) {
+            char lastMove = moves.pop();
+            if (lastMove == FORWARD) {
+                distanceCovered++;
+                continue;
+            }
+
+            if (numberOfEqualTurns == 0) {
+                numberOfEqualTurns++;
+                directionToCompare = lastMove;
+            } else {
+                if (lastMove != directionToCompare) {
+                    return false;
+                }
+                numberOfEqualTurns++;
+            }
+        }
+        return numberOfEqualTurns == 3;
+    }
+
+    private boolean evaluateNumberOfEqualTurns(int numberOfTurns) {
+        return evaluateNumberOfEqualTurns(numberOfTurns, 32);
+    }
+
+    /***
+     * Changes up the direction bias every two turns which achieves a rough zig-zag pattern
+     * @return the next direction bias
+     */
+    protected char switchBias(boolean forcedSwitch) {
+        if(!evaluateNumberOfEqualTurns(2) && !forcedSwitch) {
+            return directionBias;
+        }
+        directionBias = switch (directionBias) {
+            case LEFT -> {
+                directionBias = RIGHT;
+                yield RIGHT;
+            }
+            case RIGHT -> {
+                directionBias = LEFT;
+                yield LEFT;
+            }
+            default -> directionBias;
+        };
+        return directionBias;
+    }
+
+    protected char switchBias() {
+        return switchBias(false);
+    }
+
+    private boolean checkFrontCollisions(View view) {
+        return view.data.charAt(2) != '*' &&
+               view.data.charAt(7) != '*';
+    }
+
+    private boolean checkSideCollisions(View view, int side) {
+        if (side == -1) {
+            return view.data.charAt(11) != '*';
+        } else if (side == 1) {
+            return view.data.indexOf(13) != '*';
+        }
+        return false;
+    }
+
+    protected int scanView(View view) {
+        if (view.data.contains("@")) {
+            int stone = view.data.indexOf("@") + 1;
+
+            // Check Front:
+            switch (stone) {
+                case 3:
+                    tailLength++;
+                    return 0;
+                case 8:
+                    return 0;
+            }
+
+            // If possible, prefer direction Bias
+            if (directionBias == LEFT) {
+                switch (stone) {
+                    case 11, 12: return checkSideCollisions(view, -1)? -1 : 3; // left
+                    case 14, 15: return checkSideCollisions(view, 1)?   1 : 3; // right
+                }
+            } else {
+                switch (stone) {
+                    case 14, 15: return checkSideCollisions(view, 1)?   1 : 3; // right
+                    case 11, 12: return checkSideCollisions(view, -1)? -1 : 3; // left
+                }
+            }
+        }
+        return 3;
+    }
+}