BotRoss/src/RumbleBot.java

import records.Move;

import java.util.LinkedList;
import java.util.Queue;
import java.util.Random;

public class RumbleBot extends Bot {
    protected final static String obstacles = "~#X*";
    protected final static String players = "v^<>";
    protected final static String targets = players + "o";

    protected Random random = new Random();
    protected int steps = 0;

    public static void main(String[] args) {
        if (args.length == 0) {
            String[] dummyArgs = {"localhost", "63187"};
            for (int i = 0; i < 5; i++) {
                new Thread(new EnemyBot(dummyArgs)).start();
            }
        }

        Bot bot = new RumbleBot(args);
        bot.run();
    }

    protected RumbleBot(String[] args) {
        super(args);
    }

    @Override
    protected char nextMove(View view) {
        int size = view.width;
        String data = view.data;
        char[][] grid = dataToGrid(data, size);

        if (isInLineOfSight(grid)) {
            return 'f';
        } else if (data.contains("v") || data.contains("^") || data.contains("<") || data.contains(">")) {
            return breadthFirstSearch(grid);
        } else {
            return walkAround(grid);
        }
    }

    protected char[][] dataToGrid(String data, int size) {
        char[][] grid = new char[size][size];
        for (int i = 0; i < data.length(); i++) {
            char c = data.charAt(i);
            if (Character.isUpperCase(c) && c != 'X') c = 'A';
            grid[i % size][i / size] = c;
        }
        return grid;
    }

    protected void markFiringLines(char[][] grid) {
        int[][] dir = {{0, -1}, {0, 1}, {1, 0}, {-1, 0}};
        int size = grid.length;

        for (int x = 0; x < size; x++) {
            for (int y = 0; y < size; y++) {

                switch (grid[x][y]) {
                    case '^' -> markLine(grid, x, y, dir[0], '*', false);
                    case 'v' -> markLine(grid, x, y, dir[1], '*', false);
                    case '>' -> markLine(grid, x, y, dir[2], '*', false);
                    case '<' -> markLine(grid, x, y, dir[3], '*', false);
                }

                if (players.contains("" + grid[x][y])) {
                    for (int[] direction : dir) {
                        markLine(grid, x, y, direction, 'o', true);
                    }
                }

            }
        }
    }

    private void markLine(char[][] grid, int x, int y, int[] dir, char c, boolean block) {
        int size = grid.length;
        x += dir[0];
        y += dir[1];
        while (x >= 0 && x < size && y >= 0 && y < size && !obstacles.contains("" + grid[x][y])) {
            if (grid[x][y] == 'A' && block) break;
            if (grid[x][y] == '.') {
                grid[x][y] = c;
            }
            x += dir[0];
            y += dir[1];
        }
    }

    protected boolean isInLineOfSight(char[][] grid) {
        int size = grid.length;
        for (int y = size / 2; y >= 0; y--) {
            if (players.contains("" + grid[size / 2][y]))
                return true;

            if (obstacles.contains("" + grid[size / 2][y]))
                break;
        }
        return false;
    }

    protected char walkAround(char[][] grid) {
        int size = grid.length;
        if (steps == 0) {
            steps = random.nextInt(20);
            return random.nextBoolean() ? '<' : '>';
        } else {
            steps--;
            return obstacles.contains("" + grid[size / 2][size / 2 - 1]) ? '<' : '^';
        }
    }

    protected char breadthFirstSearch(char[][] grid) {
        markFiringLines(grid);
        int size = grid.length;
        int start = size / 2;

        for (int y = 0; y < size; y++) {
            for (char[] chars : grid) System.err.print(chars[y]);
            System.err.println();
        }

        boolean[][] visited = new boolean[size][size];
        Queue<Move> queue = new LinkedList<>();

        int[][] directions = {{0, -1}, {0, 1}, {1, 0}, {-1, 0}};
        char[] commands = {'^', 'v', '>', '<'};
        for (int i = 0; i < 4; i++) {
            queue.add(new Move(start + directions[i][0], start + directions[i][1], commands[i]));
        }

        while (!queue.isEmpty()) {
            Move move = queue.poll();
            if (move.x() < 0 || move.x() >= size || move.y() < 0 || move.y() >= size || visited[move.x()][move.y()]) continue;
            visited[move.x()][move.y()] = true;
            if (obstacles.contains("" + grid[move.x()][move.y()])) continue;
            if (targets.contains("" + grid[move.x()][move.y()])) return move.direction();

            for (int[] direction : directions) {
                queue.add(new Move(move.x() + direction[0], move.y() + direction[1], move.direction()));
            }
        }

        System.err.println("No path found");
        return walkAround(grid);
    }

}