Slime: The Territory War

Question

You are a glob of slime. Naturally, being slime, you want to ooze over as much area as possible. But there are 3 other slimes who want to do the exact same thing. Who will be the superior slime?

Description

All slimes will be gathered into one arena. The judges (i.e. the control program) will go through an exhaustive list of all possible 4-slime combinations, place them on the corners of a table, and observe to see which slime oozes out over the most area.

Your slimes can do one of 3 actions each turn: spread out, jump, or merge. Further description on what these mean will be provided in the Output section.

Board / Arena

The arena will be a square board (currently 8x8, but this may change in the future). Here is an example arena of a game in progress:

11111222
11111444
11.22444
.1222.4.
333.3244
33333.44
333...44
333....4

Slime is represented by the numbers 1 through 4 (players 1 to 4), and empty space is represented by a dot (.). Initially, the board starts out as all empty space except for a single unit of player 1's slime in the top left corner, player 2 in the top right, player 3 in the bottom left, and player 4 in the bottom right.

Coordinates are represented by 0-based row and column index, for readability in the code. For example, the coordinates (3, 6) represent the 7th square in the 4th row (in the above example, a 4). (This makes it easier to access squares: board[coords.x][coords.y].) Here's a visual illustration:

(0, 0) (0, 1) (0, 2)
(1, 0) (1, 1) (1, 2)
(2, 0) (2, 1) (2, 2)

Input

Your program's input will be which player you are (1, 2, 3, or 4), a comma (,), then the content of the board / arena (with newlines replaced with commas). For example, if you were player 3 in the above scenario, your input would be:

3,11111222,11111444,11.22444,.1222.4.,333.3244,33333.44,333...44,333....4

Output

Your program must output 4 integers. The first two are the row and column index respectively of the slime you would like to move, and the next two are the row and column index of where you want to move them.

There are three choices you have on each turn: Spread out, jump, or merge.

• Spread

  To spread, the target coordinates must be exactly one square away from the slime being moved, and the square at the target coordinates must be empty space. When spreading, a new slime is created at the target coordinates and the old slime is not removed. After the new slime is created, all enemy slimes in the 8 squares around this new slime are converted to the player that moved.

  For example, with the board in Fig. 1, if player 1 were to output 0 1 1 2, the result would be the board in Fig. 2.

  1.         2.
    11.22      11.12
    1..22      1.112
    ..22.      ..11.
    .....      .....
  

• Jump

  To jump, the target coordinates must be exactly two squares away from the slime being moved, and the square at the target coordinates must be empty space. When jupming, a new slime is created at the target coordinates and the old slime is removed. After the new slime is created, all enemy slimes in the 8 squares around this new slime are converted to the player that moved.

  For example, with the board in Fig. 1, if player 1 were to output 0 1 2 3, the result would be the board in Fig. 2.

  1.         2.    
    11..2      1...2
    1...2      1...1
    ....2      ...11
    ...22      ...11
  

• Merge

  To merge, the target coordinates must be exactly one square away from the slime being moved, and the square at the target coordinates must be the same player's slime. When merging, the old slime is removed. Then, all empty spaces in the 8 squares around the target slime are converted to the player that moved (not including the old slime being moved).

  For example, with the board in Fig. 1, if player 1 were to output 0 1 1 2, the result would be the board in Fig. 2.

  1.         2.
    11..2      1.112
    1.1.2      11112
    ....2      .1112
    ..222      ..222
  

You can also pass, by simply outputting invalid coordinates (ex. 0 0 0 0).

Rules and constraints

Additional rules are:

• You may read and write files within your own folder in order to persist data (submissions will be stored in players/YourBotName/yourBotName.language), but you may not modify or access anything else outside of it. Internet access is prohibited.
• Your submission may not be coded specifically to help or hurt another submission. (You may have multiple submissions, but they must not specifically interact with each other in any way.)
• Your submission must take no more than 0.1 seconds per turn. If your submission takes 0.105 seconds occasionally, that's fine, but it may not consistently take significantly longer than this time limit. (This is mainly a sanity check to avoid testing taking an overly long time.)
• Your submission must not be an exact duplicate (i.e. use the exact same logic) of another, even if it's in a different language.
• Your submission must be a serious submission. This is opinion-based, but if your submission is clearly not attempting to solve the challenge (ex. if you pass every turn), it will be disqualified.

If your submission breaks any of these rules or doesn't follow the specification, it will be disqualified, removed from playerlist.txt, and the game will restart from the beginning. If your submission is disqualified, I will leave a comment on your post explaining why. Otherwise, your submission will be added to the leaderboard. (If you don't see your submission on the leaderboard, have no explanatory comment on your post, and posted your submission before the "Last updated" time below, please tell me! I may have inadvertently overlooked it.)

In your entry, please include:

• A name.
• A shell command to run your program (for example, java MyBot.java, ruby MyBot.rb, python3 MyBot.py, etc.).
  • Note that the input (your player and map) will be appended to this as a command line argument.
  • Programs will be tested on Ubuntu 14.04, so make sure your code can be run (freely) on it.
• A version number, if your code works differently on different versions of your language.
• Your bot's code.
• Instructions on how to compile the code, if necessary.

Controller code / testing, example bot

The controller code is written in C++, and can be found on Github. Further instructions on how to run and test your code can be found there.

simplebot.rb, a very simple bot that spreads or jumps a random slime to a random location each turn, is also posted on Github.

Scoring and leaderboard

When all squares on the board are filled, the game ends and scores are calculated. The final score of a player is the amount of squares that contain their slime at the end of the game. If 2000 turns have passed (500 for each player) and the game still isn't over, the game will end anyway and the scores will be reported as if the game had ended.

At the end of the tournament, the scores from all games will averaged to calculate each player's final score, which will be posted on the leaderboard. There is no submission deadline; I'll continue to update the leaderboard periodically as new submissions come in.

4 submissions are required until a real leaderboard appears.

+--------------------------+-----------+--------------------+
| Name                     | Avg Score | Last Updated (UTC) |
+--------------------------+-----------+--------------------+
| GreedySlime              | 47.000    | Jul 22 10:27 PM    |
| Jumper                   | 12.000    | Jul 22 10:27 PM    |
| ShallowBlue              | 5.000     | Jul 22 10:27 PM    |
| Lichen                   | 0.000     | Jul 22 10:27 PM    |
+--------------------------+-----------+--------------------+

Last updated: Jul 22 10:27 PM (UTC).

Answer 1

GreedySlime

Simply makes the move that produces the greatest net gain of slime units.

Note that this is written in Python 2.x.

def gen_moves(board, pos):
    """Generate valid moves for a given position.

    Return value is a tuple of the form
       (type, from_x, from_y, to_x, to_y)

    The move 'type' is a single character with:
        - 's' = spread
        - 'j' = jump
        - 'm' = merge
    """

    N = len(board)
    x0, y0 = pos
    player = board[x0][y0]

    for i in -2,-1,0,1,2:
        for j in -2,-1,0,1,2:
            if (i == 0 and j == 0):
                continue

            x1, y1 = x0 + i, y0 + j

            if not ((0 <= x1 < N) and (0 <= y1 < N)):
                continue

            c = board[x1][y1]

            if -1 <= i <= 1 and -1 <= j <= 1:
                if c == '.':
                    yield ('s', x0, y0, x1, y1)
                elif c == player:
                    yield ('m', x0, y0, x1, y1)
            else:
                if c == '.':
                    yield ('j', x0, y0, x1, y1)

def eval_move(board, move, initial_net={'s': 1, 'j': 0, 'm': -1}):
    """Evaluates given move in given context.

    - Assumes move is valid.
    - `move` argument is a tuple of the form
       (type, from_x, from_y, to_x, to_y)
    - The move 'type' is a single character with:
        - 's' = spread
        - 'j' = jump
        - 'm' = merge
    """

    N = len(board)
    move_type = move[0]
    x0, y0, x1, y1 = move[1:]
    player = board[x0][y0]

    net = initial_net[move_type]
    for i in -1,0,1:
        for j in -1,0,1:
            if (i == 0 and j == 0):
                continue

            x2, y2 = x1 + i, y1 + j

            if not ((0 <= x2 < N) and (0 <= y2 < N)):
                continue

            c = board[x2][y2]

            if (move_type == 'm' and c == '.') or (move_type != 'm' and c != player and c != '.'):
                net += 1

    return net

def main():
    from sys import argv
    data = argv[1]

    player, board = data.split(',', 1)
    board = map(list, board.split(','))
    N = len(board)

    all_pos_gen = ((a,b) for a in range(N) for b in range(N) if board[a][b] == player)
    all_move_gen = (move for pos in all_pos_gen for move in gen_moves(board, pos))
    move = max(all_move_gen, key=lambda move: eval_move(board, move))

    print move[1], move[2], move[3], move[4]

if __name__ == "__main__":
    main()

---

Example run (using the example given in the challenge description, and assuming the code is saved in a file called slime.py):

$ python slime.py 3,11111222,11111444,11.22444,.1222.4.,333.3244,33333.44,333...44,333....4
4 0 2 2

Answer 2

Shallow Blue

Shallow blue tries to figure out what might happen in the future by doing an exhaustive tree-search of possible moves, unfortunately, he doesn't get any further than his next turn. He then slaps some half-assed score on each possible boardstate after his next turn, calculates a score for each individual branch with an equally ridiculous formula and: voila the ideal move is known!

EDIT: The original code ran waay too slowly so I modified it so that it only takes a random sample of all possible moves. It will try almost all moves when there are little moves possible and a smaller percentage when there are more moves possible.

import java.awt.Point;  
    
    public class ShallowBlue {
        private static final int MAX_ROUNDS = 5, PLAYERS = 4;
        static int me = 0;
    
        public static void main(String[] args) {
            if (args[0] == null) {
                return;
            }
    
            me = Integer.parseInt(args[0].split(",", 2)[0]);
    String board = args[0].split(",", 2)[1];

    System.out.println(getBestMove(board, me, MAX_ROUNDS - 1));
}

private static String getBestMove(String board, int player, int rounds) {
    String [] boards = new String[24];
    int checkedBoards = 1;
    char playerChar = Integer.toString(player).charAt(0);
    String tempMove = getMove(0, 0, 0, 0);
    String tempBoard = calculateMove(board, tempMove); 
    boards[0] = tempBoard;
    String bestMove = tempMove;
    double us = numberOfUs(board, playerChar); 
    double skip = (us*2.5/(us*2.5 + 1))/4 + 0.735;
    if (rounds == MAX_ROUNDS - 2) {
        skip = skip*skip;
    }

    float bestScore, worstScore, averageScore, tempScore;
    int scores;

    if (rounds == 0) {
        tempScore = calculateScore(tempBoard, MAX_ROUNDS - rounds - 1);
    } else {
        tempScore = getScore(getBestMove(tempBoard, player%PLAYERS + 1, rounds - 1));
    }

    scores = 1;
    bestScore = tempScore;
    worstScore = tempScore;
    averageScore = tempScore;

    for (int x = 0; x < 8; x++) {
        for (int y = 0; y < 8; y++) {
            if (getCharAt(board, x, y) == playerChar) {
                Point[] possibleMergers = getNeighboringMatches(board, new Point(x, y), playerChar);
                if (possibleMergers[0] != null) {
                    tempMove = getMove(possibleMergers[0].x, possibleMergers[0].y, x, y); 
                    tempBoard = calculateMove(board, tempMove);
                    if (addIfUnique(boards, tempBoard, checkedBoards)) {
                        checkedBoards++;
                        if ((rounds != MAX_ROUNDS - 1) && (rounds == 0 || Math.random() < skip)) {
                            tempScore = calculateScore(tempBoard, MAX_ROUNDS - rounds - 1);
                        } else {
                            tempScore = getScore(getBestMove(tempBoard, player%PLAYERS + 1, rounds - 1));
                        }

                        if (tempScore > bestScore) {
                            bestMove = tempMove;
                        }
                        bestScore = Math.max(tempScore, bestScore);
                        worstScore = Math.min(tempScore, worstScore);

                        scores++;
                        averageScore = (averageScore*(scores - 1) + tempScore)/scores;
                    }
                }
            } else if (getCharAt(board, x, y) == '.') {
                Point[] possibleSpreaders = getNeighboringMatches(board, new Point(x, y), playerChar);
                int i = 0;
                while (i < possibleSpreaders.length && possibleSpreaders[i] != null) {
                    tempMove = getMove(possibleSpreaders[i].x, possibleSpreaders[i].y, x, y); 
                    tempBoard = calculateMove(board, tempMove);
                    if ((rounds != MAX_ROUNDS - 1) && (rounds == 0 || Math.random() < skip)) {
                        tempScore = calculateScore(tempBoard, MAX_ROUNDS - rounds - 1);
                    } else {
                        tempScore = getScore(getBestMove(tempBoard, player%PLAYERS + 1, rounds - 1));
                    }

                    if (tempScore > bestScore) {
                        bestMove = tempMove;
                    }
                    bestScore = Math.max(tempScore, bestScore);
                    worstScore = Math.min(tempScore, worstScore);

                    scores++;
                    averageScore = (averageScore*(scores - 1) + tempScore)/scores;
                    
                    i++;
                }
                Point[] possibleJumpers = getNextNeighboringMatches(board, new Point(x, y), playerChar);
                i = 0;
                while (i < possibleJumpers.length && possibleJumpers[i] != null) {
                    tempMove = getMove(possibleJumpers[i].x, possibleJumpers[i].y, x, y); 
                    tempBoard = calculateMove(board, tempMove);
                    if ((rounds != MAX_ROUNDS - 1) && (rounds == 0 || Math.random() < skip)) {
                        tempScore = calculateScore(tempBoard, MAX_ROUNDS - rounds - 1);
                    } else {
                        tempScore = getScore(getBestMove(tempBoard, player%PLAYERS + 1, rounds - 1));
                    }

                    if (tempScore > bestScore) {
                        bestMove = tempMove;
                    }
                    bestScore = Math.max(tempScore, bestScore);
                    worstScore = Math.min(tempScore, worstScore);

                    scores++;
                    averageScore = (averageScore*(scores - 1) + tempScore)/scores;
                    
                    i++;
                }
            }
        }
    }

    if (rounds == MAX_ROUNDS - 1) {
        return (bestMove);
    } else {
        return getScoreString(bestScore, worstScore, averageScore);
    }
}

private static int numberOfUs(String board, char playerChar) {
    int us = 0;
    
    for (int i = 0; i < board.length(); i++ ) {
         if (board.charAt(i) == playerChar) {
            us++;
        }
    }
    
    return us;
}

private static float calculateScore(String board, int roundsPassed) {
    int empties = 0;
    int us = 0;
    int enemy1 = 0;
    int enemy2 = 0;
    int enemy3 = 0;
    for (int i = 0; i < board.length(); i++ ) {
        if (board.charAt(i) == '.') {
            empties++;
        } else if (board.charAt(i) == Integer.toString(me).charAt(0)) {
            us++;
        } else if (board.charAt(i) == Integer.toString(me%PLAYERS + 1).charAt(0)) {
            enemy1++;
        } else if (board.charAt(i) == Integer.toString(me%PLAYERS + 2).charAt(0)) {
            enemy2++;
        } else if (board.charAt(i) == Integer.toString(me%PLAYERS + 3).charAt(0)) {
            enemy3++;
        }
    }
    
    if (us != 0) {
        us += roundsPassed;
    }
    
    if (enemy1 != 0) { 
        enemy1 = enemy1 + (roundsPassed + 3)%PLAYERS;
    }
    
    if (enemy2 != 0) { 
        enemy2 = enemy2 + (roundsPassed + 2)%PLAYERS;
    }
    
    if (enemy3 != 0) { 
        enemy3 = enemy3 + (roundsPassed + 1)%PLAYERS;
    }

    return us*(empties + 1)/(Math.max(Math.max(enemy1, enemy2), enemy3) + 1);
}

private static float getScore(String scoreString) {
    float bestScore, worstScore, averageScore;
    String[] scores = new String[3];

    scores = scoreString.split(",");
    bestScore = Float.parseFloat(scores[0]);
    worstScore = Float.parseFloat(scores[1]);
    averageScore = Float.parseFloat(scores[2]);


    return (float) Math.sqrt(Math.sqrt(bestScore*averageScore*worstScore*worstScore));
}

private static String getScoreString(float bestScore, float worstScore, float averageScore) {
    return Float.toString(bestScore) + ',' + Float.toString(worstScore) + ',' + Float.toString(averageScore);
}

private static boolean addIfUnique(String[] boards, String board, int checkedBoards) {
    int i = 0;

    while (i < boards.length && boards[i] != null) {
        if (boards[i].equals(board)) {
            return false;
        }
        i++;
    }
    
    if (i < boards.length) {
        boards[i] = board;
    } else {
        boards[checkedBoards%boards.length] = board;
    }

    return true;
}

private static String calculateMove(String board, String move) {
    int x1 = Integer.parseInt(Character.toString(move.charAt(0)));
    int y1 = Integer.parseInt(Character.toString(move.charAt(2)));
    int x2 = Integer.parseInt(Character.toString(move.charAt(4)));
    int y2 = Integer.parseInt(Character.toString(move.charAt(6)));

    if ((Math.abs(y1 - y2) == 2 || Math.abs(x1 - x2) == 2) 
            &&  getCharAt(board, x2, y2) == '.') {
        Point[] enemies = new Point[8];

        enemies = getNeighboringEnemies(board, new Point(x1, y1), Integer.parseInt(Character.toString(getCharAt(board, x1, y1))));

        board = replace(board, enemies, getCharAt(board, x1, y1));
        Point[] middle = {new Point(x1, y1)};
        board = replace(board, middle, '.');
    }

    if ((Math.abs(y1 - y2) == 1 || Math.abs(x1 - x2) == 1)) { 
        if (getCharAt(board, x2, y2) == '.' || getCharAt(board, x1, y1) == getCharAt(board, x2, y2)) {
            boolean merge = true;
            if (getCharAt(board, x2, y2) == '.') {
                merge = false;
            }

            Point[] spaces = new Point[8];
            spaces = getNeighboringMatches(board, new Point(x1, y1), '.');
            board = replace(board, spaces, getCharAt(board, x1, y1));

            if (merge) {
                Point[] source = {new Point(x1, y1)};
                board = replace(board, source, '.');
            }
        }
    }

    return board;
}

private static String replace(String board, Point[] targets, char source) {
    int i = 0;

    while (i < targets.length && targets[i] != null) {
        if (targets[i].x == 7 && targets[i].y == 7) {
            board = board.substring(0, getIndexAt(targets[i].x, targets[i].y)) + source;
        } else if (targets[i].x == 0 && targets[i].y == 0) {
            board = source + board.substring(getIndexAt(targets[i].x, targets[i].y) + 1);
        } else {
            board = board.substring(0, getIndexAt(targets[i].x, targets[i].y)) + source + board.substring(getIndexAt(targets[i].x, targets[i].y) + 1);
        }
        i++;
    }

    return board;
}

private static Point[] getNeighboringMatches(String board, Point coord, char match) {
    Point[] matches = new Point[8];

    int i = 0;
    for (int x = coord.x - 1; x <= coord.x + 1; x++) {
        for (int y = coord.y - 1; y <= coord.y + 1; y++) {
            if ((y != coord.y || x != coord.x ) && getCharAt(board, x, y) == match){
                matches[i] = new Point(x, y);
                i++;
            }
        }
    }

    return matches;
}

private static Point[] getNeighboringEnemies(String board, Point coord, int player) {
    Point[] enemies = new Point[8];

    for (int i = 1; i <= PLAYERS; i++){
        enemies = mergeArr(enemies, getNeighboringMatches(board, coord, Integer.toString((player + i - 1)%PLAYERS + 1).charAt(0)));
    }

    return enemies;
}

private static Point[] getNextNeighboringMatches(String board, Point coord, char match) {
    Point[] matches = new Point[16];

    int i = 0;
    for (int x = coord.x - 2; x <= coord.x + 2; x++) {
        for (int y = coord.y - 2; y <= coord.y + 2; y++) {
            if ((Math.abs(y - coord.y) == 2 || Math.abs(x - coord.x) == 2) && getCharAt(board, x, y) == match){
                matches[i] = new Point(x, y);
                i++;
            }
        }
    }

    return matches;
}

private static char getCharAt(String board, int x, int y) {

    if (x >= 0 && x < 8 && y >= 0 && y < 8) {
        return board.charAt(9*x + y);
    } else {
        return '\0';
    }
}

private static int getIndexAt(int x, int y) {
    return 9*x + y;
}

private static Point[] mergeArr(Point[] arr1, Point[] arr2) {
    int i = 0;
    int j = 0;

    while (i < arr1.length && arr1[i] != null) {
        i++;
    }

    while (j < arr2.length && arr2[j] != null) {
        arr1[i + j] = arr2[j];
        j++;
    }

    return arr1;
}

private static String getMove(int x1, int y1, int x2, int y2) {
    return Integer.toString(x1) + " " + Integer.toString(y1) + " " + Integer.toString(x2) + " " + Integer.toString(y2);
    }
}

Answer 3

Jumper

Likes to jump, even more so towards the middle.

Will pass if no slimes can jump.

C++, Should compile simply with g++ jumper.cpp -o jumper

#include <math.h>
#include <algorithm>
#include <iostream>
#include <string>
#include <sstream>
#include <vector>
#define maxn(x, y) ((x) > (y) ? (x) : (y))
#define absn(x) ((x) < 0 ? -(x) : (x))
class Board {
 public:
    Board(std::string input_string);
    void Move();
 private:
    void ParseBoardState(std::string console_string);
    int Slimes(int cell);
    void GetXY(int cell, int& r, int& c);
    bool CanJumpFromHere(int cell, int& jump_to_cell, int& rad);
    int CalcRadius(int cell);
    bool CheckJumpDist(int x, int y);

    int player_num_;
    std::size_t board_dim_;
    std::size_t sq_;
    std::vector< std::vector<int> > slimes_;
};
Board::Board(std::string input_string) 
    : player_num_(0), 
      board_dim_(0),
      slimes_() {
    board_dim_ = std::count(input_string.begin(), input_string.end(), ',');
    sq_ = board_dim_ * board_dim_;
    std::istringstream temp(input_string.substr(0,1));
    temp >> player_num_;
    ParseBoardState(input_string);
}
void Board::ParseBoardState(std::string console_string) {
    int place = 0;
    for (std::size_t row = 0; row < board_dim_; ++row ) {
        slimes_.push_back(std::vector<int>());
        place = console_string.find(",",place+1);
        std::string temp2 = console_string.substr(place+1, 8);
        for (std::size_t col = 0; col < board_dim_; ++col ) {
            int sl = 0;
            std::istringstream bint(temp2.substr(col,1));
            bint >> sl;
            slimes_[row].push_back(sl);
        }
    }
}
int Board::Slimes(int cell) {
    int r = 0;
    int c = 0;
    GetXY(cell, r, c);
    return  slimes_[r][c];
}
void Board::GetXY(int cell, int& r, int& c) {
    for (std::size_t row = 0; row < board_dim_; ++row ) {
        for (std::size_t col = 0; col < board_dim_ ; ++col ) {
            if ( (row * board_dim_ + col) == cell) {
                r = row;
                c = col;
            }
        }
    }
}
void Board::Move() {

    // go through each cell:
    int index = 0;
    int jump_to_cell = 0;
    int rad = 0;
    int min_rad = 1000;
    int best_jump_to = -1;
    int best_jump_from = -1;
    for (int c = 0; c < sq_; ++c) {
        if (Slimes(c) == player_num_) {
            if (CanJumpFromHere(c, jump_to_cell , rad)) {
                if (rad < min_rad) {
                    best_jump_from = c;
                    best_jump_to = jump_to_cell;
                    min_rad = rad;
                }
                index += 1;
            }
        }
    }

    int ret_row = 0;
    int ret_col = 0;

    if (index == 0) {
        // can't jump so dont bother:
        std::cout << "0 0 0 0" << std::endl;
    } else {
        GetXY(best_jump_from, ret_row, ret_col);
        std::cout << ret_row << " " << ret_col  << " ";
        GetXY(best_jump_to, ret_row, ret_col);
        std::cout << ret_row << " " << ret_col << std::endl;
    }
}
bool Board::CanJumpFromHere(int cell, int& ret_jump_to_cell, int & ret_rad) {
    int r = 0;
    int c = 0;
    int rad = 10000;
    int jump_to_cell = 0;
    int rad_min_for_this_cell = 10000;
    GetXY(cell, r, c);
    bool jumpable = false;
    for (int row_test = -2; row_test < 3; ++row_test) {
        for (int col_test = -2; col_test < 3; ++col_test) {
            if ( (r + row_test) > 0 &
                 (r + row_test) < board_dim_ &&
                 (c + col_test) > 0 &&
                 (c + col_test) < board_dim_ &&
                 (CheckJumpDist(col_test, row_test)) &&
                 (slimes_[r+row_test][c+col_test] == 0)) {

                jumpable = true;
                jump_to_cell = (r + row_test) * board_dim_ + c + col_test;
                rad = CalcRadius(jump_to_cell);

                if (rad < rad_min_for_this_cell) {
                    ret_rad = rad;
                    ret_jump_to_cell = jump_to_cell;
                    rad_min_for_this_cell = ret_rad;
                }
            }
        }
    }
    return jumpable;
}
bool Board::CheckJumpDist(int x, int y) {
    int maxDelta = maxn(absn(x), absn(y));
    if (maxDelta <= 0 || maxDelta > 2) {
        return false;
    } else {
        return true;
    }
}
int Board::CalcRadius(int cell) {
    int r = 0;
    int c = 0;
    GetXY(cell, r, c);
    // unnecessary accuracy considering how bad this bot is:
    float mid = static_cast<float>(board_dim_) / 2;
    float rad = sqrt((r - mid) * (r - mid) + (c-mid)*(c-mid));
    int ret = static_cast<int>(rad + 0.5);
    return ret;
}
int main(int argc, char* argv[]) {
    if (argc != 2) {
        return 0;
    } else {
        std::string input_string(argv[1]);
        Board board(input_string);
        board.Move();
    }
    return 0;
}

I stole your move verification sorry. Also I gave up on correct coding practices just after I started, so don't look. However, it seems to run on any size of board.

Answer 4

DeathSlime:

Description: Tries to hunt the weakest enemy and destroy them. Repeat.

How to run: ruby DeathSlime.rb

Ruby Version: 2.1.2

#!/usr/bin/env ruby
class PlayerPosition;
  attr_accessor :x, :y;
  def initialize(x, y) @x = x; @y = y; end
  def distance(pos) Math.sqrt((pos.x - @x)**2 + (pos.y - @y)**2); end
end

class Board
  attr_reader :player, :empty_positions
  def initialize(player_id, game_state_string)
    @player_positions = {}
    @empty_positions = []

    @enemies = []
    @player = Player.new

    row = 0
    col = 0
    game_state_string.chars.each do |tile|
      row += 1 and col = 0 and next if tile == ','
      @empty_positions << PlayerPosition.new(col, row) and col += 1 and next if tile == '.'

      @player_positions[tile] ||= []
      @player_positions[tile] << PlayerPosition.new(col, row)
      col += 1
    end

    @player_positions.each do |id, positions|
      @enemies << Player.new(id, positions) if id != player_id
      @player = Player.new(id, positions) if id == player_id
    end
  end

  def border_space(player_positions, possible_border, allowance = 1)
    near = []
    possible_border.each do |border|
      is_near = false
      player_positions.each {|pos| is_near = true and break if pos.distance(border) <= allowance}
      near << border if is_near
    end
    near
  end

  def closest_to(player_positions, enemy_positions)
    player_closest_block = nil
    shortest_distance = 1000
    enemy_closest_block = nil
    player_positions.each do |player|
      enemy_positions.each do |enemy|
        if player.distance(enemy) < shortest_distance
          shortest_distance = player.distance(enemy)
          enemy_closest_block = enemy
          player_closest_block = player
        end
      end
    end
    return player_closest_block, enemy_closest_block
  end

  def empty_space_near(player_positions, allowance = 1); border_space(player_positions, @empty_positions, allowance); end
  def weakest_enemy; @enemies.select{|enemy| !enemy.dead? }.sort {|x,y| x.strength <=> y.strength}.first; end
end

class Player
  attr_reader :positions
  def initialize(id = -1, positions = []); @id = id; @positions = positions; end
  def dead?; @positions.length == 0; end
  def strength; @positions.length; end
  def can_hurt?(enemy)
    is_close_enough = false
    self.positions.each do |my_pos|
      enemy.positions.each {|enemy_pos| is_close_enough = true and break if my_pos.distance(enemy_pos) <= 2 }
    end
    is_close_enough
  end
end




class DeathSlime

  def initialize(arg_string)
    game_state = arg_string[2..-1]
    player_id = arg_string[0]
    @board = Board.new(player_id, game_state)
  end

  def attack
    if @board.weakest_enemy
      try_to_spread_to_weakest || try_to_jump_to_weakest || try_to_merge_to_weakest || try_to_move_to_weakest
    else
      try_to_move if @empty_positions.length > 0
    end
  end


  def try_to_spread_to_weakest
    mine = @board.empty_space_near(@board.player.positions, 1)
    theirs = @board.empty_space_near(@board.weakest_enemy.positions, 1)
    target_space = mine.detect{|space| theirs.include?(space) }
    return move(@board.closest_to(@board.player.positions, [target_space]).first, target_space) if target_space
    false
  end

  def try_to_jump_to_weakest
    mine = @board.empty_space_near(@board.player.positions, 2)
    theirs = @board.empty_space_near(@board.weakest_enemy.positions, 1)
    target_space = mine.detect{|space| theirs.include?(space) }
    return move(@board.closest_to(@board.player.positions, [target_space]).first, target_space) if target_space
    false
  end

  def try_to_merge_to_weakest
    definite_border = nil
    definite_merge = nil
    possible_border = @board.border_space(@board.weakest_enemy.positions, @board.player.positions)
    possible_border.each do |border|
      possible_merges = @board.border_space([ border ], @board.player.positions.select{|space| space != border })
      definite_merge = possible_merges.first and definite_border = border and break if possible_merges.length > 0
    end
    return move(definite_merge, definite_border) if definite_border && definite_merge
    false
  end

  def try_to_move_to_weakest
    player_closest, enemy_closest = @board.closest_to(@board.player.positions, @board.weakest_enemy.positions)
    spreading_distance = @board.empty_space_near([player_closest], 1)
    jumping_distance = @board.empty_space_near([player_closest], 2)
    theirs = @board.empty_space_near(@board.player.positions, 2)

    spreading_space = spreading_distance.detect{|space| theirs.include?(space) }
    return move(@board.closest_to(@board.player.positions, [spreading_space]).first, spreading_space) if spreading_space

    jumping_space = jumping_distance.detect{|space| theirs.include?(space) }
    return move(@board.closest_to(@board.player.positions, [jumping_space]).first, jumping_space) if jumping_space

    return move(@board.closest_to(@board.player.positions, [spreading_distance]).first, spreading_distance) if spreading_distance.length > 0
    return move(@board.closest_to(@board.player.positions, [jumping_distance]).first, jumping_distance) if jumping_distance.length > 0

    #merge randomly
    closest_enemy = @board.closest_to(@board.player.positions, @board.weakest_enemy.positions).first
    return move(@board.closest_to(@board.player.positions.select{|space| space != closest_enemy }, [closest_enemy]).first, closest_enemy)
  end

  def try_to_move
    spreading_distance = @board.empty_space_near(board.player.positions, 1)
    jumping_distance = @board.empty_space_near(board.player.positions, 2)

    return move(@board.closest_to(@board.player.positions, [spreading_distance]).first, spreading_distance) if spreading_distance.length > 0
    return move(@board.closest_to(@board.player.positions, [jumping_distance]).first, jumping_distance) if jumping_distance.length > 0
  end

  def move(start_block, end_block)
    STDOUT.write "#{start_block.x} #{start_block.y} #{end_block.x} #{end_block.y}"
    true
  end
end

slime_of_death = DeathSlime.new(ARGV[0])
slime_of_death.attack

Answer 5

Lichen

This is a bot written in R. It needs to be triggered using Rscript Lichen.R.

input <- strsplit(commandArgs(TRUE),split=",")[[1]]
me <- input[1]
arena <- do.call(rbind,strsplit(input[-1],""))
n <- sum(arena==me)
where <- which(arena==me,arr.ind=TRUE)
closest <- function(a,b){
    x <- abs(outer(a[,1],b[,1],`-`))
    y <- abs(outer(a[,2],b[,2],`-`))
    matrix(which(x<2&y<2,arr.ind=TRUE),ncol=2)
    }
if(n==0){ #No slime on the board
    out <- "0 0 0 0"
    }else if(n==1){ #One slime on the board
        x <- where[1]+c(1,-1)
        y <- where[2]+c(1,-1)
        out <- paste(where[1]-1,where[2]-1,x[x%in%2:(nrow(arena)-1)]-1,y[y%in%2:(nrow(arena)-1)]-1,sep=" ")
    }else{
        area <- apply(which(arena==me,arr.ind=TRUE),2,range,na.rm=TRUE)
        empty <- matrix(which(arena==".",arr.ind=TRUE),ncol=2)
        opponents <- c("1","2","3","4")[c("1","2","3","4")!=me]
        for(i in seq_along(opponents)){
            if(i==1){
                other <- which(arena==opponents[i],arr.ind=TRUE)
                }else{other <- rbind(other,which(arena==opponents[i],arr.ind=TRUE))}
            }
        fillable <- matrix(empty[empty[,1]%in%area[1,1]:area[2,1]&empty[,2]%in%area[1,2]:area[2,2],],ncol=2)
        enemies <- matrix(other[other[,1]%in%area[1,1]:area[2,1]&other[,2]%in%area[1,2]:area[2,2],],ncol=2)
        if(length(unique(where[,2]))==1 | length(unique(where[,2]))==1){ #Slimes form a line
            W <- closest(where,empty)
            if(nrow(W)){
                out <- paste(c(where[W[1,1],]-1,empty[W[1,2],]-1),collapse=" ")
            }else{out <- "0 0 0 0"}
        }else if(length(enemies)&length(fillable)){ #There are enemies and empty spaces in habitable area
            w <- closest(enemies, fillable)
            if(nrow(w)){
                X <- abs(where[,1]-fillable[w[1,2],1])
                Y <- abs(where[,2]-fillable[w[1,2],2])
                W <- which(X<2&Y<2)
                out <- paste(c(where[W[1],]-1,fillable[w[1,2],]-1),collapse=" ")
            }else{out <- "0 0 0 0"}
        }else if(length(fillable)){ #There are empty spaces in habitable area
            w <- closest(fillable,where)
            out <- paste(c(where[w[1,2],]-1,fillable[w[1,1],]-1),collapse=" ")
        }else{
            x <- area[!area[,1]%in%c(1,nrow(arena)),1]
            y <- area[!area[,2]%in%c(1,ncol(arena)),2]
            if(sum(arena[x+(-1:1),y+(-1:1)]==".")>1){
                w <- where[where[,1]%in%(x+c(1,-1))&where[,2]%in%(y+c(1,-1)),]
                out <- paste(w[1]-1,w[2]-1,x-1,y-1,sep=" ")
            }else{
                W <- closest(where, empty)
                if(nrow(W)){
                    out <- paste(c(where[W[1,1],]-1,empty[W[1,2],]-1),collapse=" ")
                }else{out <- "0 0 0 0"}
            }
        }
    }
cat(out)

The intended algorithm is that it tries to cover a rectangular area (filling the blank using spread). When the rectangle is complete, it merges the two slimes at one of its corner (the one the furthest from the corner of the board) to expand the "habitable" area, then fill that newly defined rectangle, etc. It does not use jump.

.....   .....   .....   .....   .....   ..333
.....   .333.   3333.   3333.   3333.   33333
333..   3333.   3333.   3333.   3333.   33.33
333..   3.33.   3.33.   3333.   3333.   3333.
333..   333..   333..   333..   3333.   3333.

If an enemy is in the habitable area and there is an empty space as well in the area, it fills the empty space next to it. If the slime that should be merged into when expanding the habitable area is surrounded by enemies, then one slime will just spread instead of this one merging.

Answer 6

CornerSlime

This slime has a notion of corners, or at least did when I first wrote it in C#, I'm not really sure any more.

Written in C++, presumably will compile fine with gcc and next to no arguments; hopefully I've not used anything MSVC specific by accident.

Tested exclusively against itself on a modified server (no fancy new C++ compiler where I am) so I have no clue how it will perform, hopefully it won't be disqualified for being too slow. There is currently no randomness in this bot, but I may add some at a later date.

This is C# ported to C++ (due to speed concerns) by someone who doesn't really know C++, and is horrendous. It starts by building an array of Cells, which it then fills with all sorts of unhelpful information about the cells around it (number of my cells, number of my slimes, that sort of thing). Then it uses this information to decide if it needs to look more closely at the information it used to create that information, and then potentially uses said information to produce a meaningful output.

#include <iostream>

#define min(a,b) a>b?b:a;
#define max(a,b) a>b?a:b;

#define null 0 // fun times

struct Cell
{
public:
    int t;
    int x, y;
    int counts1[5];
    int counts2[5];
    int ecount1;
    int ecount2;
    bool safe1;
    bool safe2;

    bool canspread;
    bool canjump;
    bool canmerge;

    bool spreadable;
    bool jumpable;
    bool mergeable;

    Cell()
    {
        for (int i = 0; i < 5; i++)
        {
            counts2[i]=counts1[i]=0;
        }
        ecount1=ecount2=0;
        safe1=safe2=mergeable=jumpable=spreadable=canmerge=canjump=canspread=false;
    }

    Cell(int tN, int xN, int yN) // not sure why I can't call () constructor here
    {
        for (int i = 0; i < 5; i++)
        {
            counts2[i]=counts1[i]=0;
        }
        ecount1=ecount2=0;
        safe1=safe2=mergeable=jumpable=spreadable=canmerge=canjump=canspread=false;

        t = tN;
        x = xN;
        y = yN;
    }

    void findOptions(int moi)
    {
        if (t == 0)
        {
            if (counts1[moi] > 0)
                spreadable = true;
            if (counts2[moi] > 0)
                jumpable = true;
        }
        else if (t == moi)
        {
            if (counts1[moi] > 0)
                mergeable = canmerge = true;
            if (counts1[0] > 0)
                canspread = true;
            if (counts2[0] > 0)
                canjump = true;
        }
    }
};

const int dim = 8;
const int hdim = 4;

int moi;
int chezMoi;

int target;
int chezTarget;

Cell cells[dim][dim];

int cornerCounts[4][5];
int totalCounts[5];

// ring ness - why why why

// end ring ness

int tlx;
int tly;
int thx;
int thy;

int alx;
int aly;
int ahx;
int ahy;

int rj;
int rstate;

void ring(int x, int y, int dist)
{   
    tlx=x-dist;
    tly=y-dist;
    thx=x+dist;
    thy=y+dist;

    alx=max(0, tlx);
    aly=max(0, tly);
    ahx=min(dim-1, thx);
    ahy=min(dim-1, thy);

    rstate = 0;
}

bool nextR(Cell** outc)
{
    if (rstate == 1)
    {
        goto state1;
    }
    if (rstate == 2)
    {
        goto state2;
    }
    if (rstate == 3)
    {
        goto state3;
    }
    if (rstate == 4)
    {
        goto state4;
    }

    if (alx == tlx)
    {
        rj = aly - 1;
        rstate = 1;
    }
state1:
    if (alx == tlx)
    {
        if (++rj <= ahy)
        {
            *outc = (cells[alx]+rj);
            return true;
        }
        alx++;
    }

    if (ahx == thx)
    {
        rj = aly - 1;
        rstate = 2;
    }
state2:
    if (ahx == thx)
    {
        if (++rj <= ahy)
        {
            *outc = (cells[ahx]+rj);
            return true;
        }
        ahx--;
    }

    if (aly == tly)
    {
        rj = alx - 1;
        rstate = 3;
    }
state3:
    if (aly == tly)
    {
        if (++rj <= ahx)
        {
            *outc = (cells[rj]+aly);
            return true;
        }
    }

    if (ahy == thy)
    {
        rj = alx - 1;
        rstate = 4;
    }
state4:
    if (ahy == thy)
    {
        if (++rj <= ahx)
        {
            *outc = (cells[rj]+ahy);
            return true;
        }
    }

    return null;
}

int cox;
int coy;

int ci;
int cj;

void corner(int idx)
{
    cox = (idx / 2) * hdim;
    coy = (idx % 2) * hdim;

    ci = 0;
    cj = -1;
}

bool nextC(Cell** outc)
{
    for (;ci < hdim;ci++)
    {
        for (;++cj < hdim;)
        {
            *outc = (cells[ci+cox]+cj+coy);
            return true;
        }
        cj = -1;
    }

    return false;
}

void cornerCount(int idx, int* c)
{
    int ox = (idx / 2) * hdim;
    int oy = (idx % 2) * hdim;

    for (int i = 0; i < hdim; i++)
    {
        for (int j = 0; j < hdim; j++)
        {
            c[cells[i+ox][j+oy].t]++;
        }
    }
}

void ringCount(int x, int y, int dist, int* c)
{
    int tlx=x-dist;
    int tly=y-dist;
    int thx=x+dist;
    int thy=y+dist;

    int alx=max(0, tlx);
    int aly=max(0, tly);
    int ahx=min(dim-1, thx);
    int ahy=min(dim-1, thy);

    if (alx == tlx)
    {
        for (int j = aly; j <= ahy; j++)
            c[cells[alx][j].t]++;
        alx++;
    }
    if (ahx == thx)
    {
        for (int j = aly; j <= ahy; j++)
            c[cells[ahx][j].t]++;
        ahx--;
    }
    if (aly == tly)
    {
        for (int i = alx; i <= ahx; i++)
            c[cells[i][aly].t]++;
    }
    if (ahy == thy)
    {
        for (int i = alx; i <= ahx; i++)
            c[cells[i][ahy].t]++;
    }
}

int trans(char c)
{
    return c<48?0:c-48;
}

std::string res(Cell* ca, Cell* cb)
{
    char buff[100]; // shhh
    sprintf_s(buff, "%d %d %d %d\n", ca->x, ca->y, cb->x, cb->y);
    return std::string(buff);
}

std::string go(char* inp)
{
    moi = trans(inp[0]);

    int a = 2;

    for (int i = 0; i < dim; i++)
    {
        for (int j = 0; j < dim; j++)
        {
            cells[i][j] = Cell(trans(inp[a]), i, j);
            a++;
        }
        a++;
    }

    // count corners and totals
    for (int i = 0; i < 4; i++)
    {
        cornerCount(i, cornerCounts[i]);
        for (int j = 0; j < 5; j++)
        {
            totalCounts[j] += cornerCounts[i][j];
        }
    }

    // count and find cell options
    for (int i = 0; i < dim; i++)
    {
        for (int j = 0; j < dim; j++)
        {
            Cell* c = cells[i]+j;

            ringCount(i, j, 1, c->counts1);
            ringCount(i, j, 2, c->counts2);

            // safeness
            for (int r = 1; r < 5; r++)
            {
                if (r != moi)
                {
                    c->ecount1 += c->counts1[r];
                    c->ecount2 += c->counts2[r];
                }
            }
            c->safe1 = c->ecount1 == 0 && c->counts1[0] == 0; // surrounded by moi
            c->safe2 = c->ecount1 == 0 && c->ecount2 == 0; // no enemies in sight

            // that funcion which does stuff
            c->findOptions(moi);
        }
    }

    // find chezMoi
    chezMoi = moi-1; // might work, can't be bothered to work it out
    for (int i = 1; i < 4; i++)
    {
        if (cornerCounts[i][moi] > cornerCounts[chezMoi][moi])
            chezMoi = i;
    }

    int best = 0;

    if (cornerCounts[chezMoi][moi] < hdim * hdim)
    {
        // fill our corner
        best = 0;
        Cell* ac = null;
        Cell* bc = null;

        corner(chezMoi);
        Cell* c;
        while (nextC(&c))
        {
            if (c->spreadable && c->ecount1 + 1 > best)
            {
                ring(c->x, c->y, 1);
                Cell* oc;
                while (nextR(&oc))
                {
                    if (oc->canspread)
                    {
                        best = c->ecount1 + 1;
                        ac = oc;
                        bc = c;
                        break;
                    }
                }
            }
            if (c->mergeable && c->counts1[0] - 1 > best)
            {
                ring(c->x, c->y, 1);
                Cell* oc;
                while (nextR(&oc))
                {
                    if (oc->safe2 && oc->canmerge && c->counts1[0] > 0)
                    {
                        best = c->counts1[0] - 1;
                        ac = oc;
                        bc = c;
                        break;
                    }
                }
            }
        }

        if (bc != null)
        {
            return res(ac, bc);
        }
    }

    // pick target (why?)
    target = -1;
    best = 0;
    for (int i = 0; i < 4; i++)
    {
        if (i == moi)
            continue;
        int cur = totalCounts[i];
        if (target == -1 || cur > best)
        {
            target = i;
            best = cur; 
        }
    }

    if (target != -1)
    {
        for (int i = 0; i < 4; i++)
        {
            if (i == chezMoi)
                continue;
            int cur = cornerCounts[i][target];
            if (chezTarget == -1 || cur > best)
            {
                chezTarget = i;
                best = cur;
            }
        }

        // attack chosen target (not sure it does this anymore...)
        best = 0;
        Cell* ac = null;
        Cell* bc = null;

        for (int i = 0; i < dim; i++)
        {
            for (int j = 0; j < dim; j++)
            {
                Cell* c = cells[i]+j;

                if (c->spreadable && c->ecount1 + 1 > best)
                {
                    ring(c->x, c->y, 1);
                    Cell* oc;
                    while (nextR(&oc))
                    {
                        if (oc->canspread)
                        {
                            best = c->ecount1 + 1;
                            ac = oc;
                            bc = c;
                            break;
                        }
                    }
                }
                if (c->jumpable && c->ecount1 - 1 > best)
                {
                    ring(c->x, c->y, 2);
                    Cell* oc;
                    while (nextR(&oc))
                    {
                        if (oc->safe2 && oc->canjump)
                        {
                            best = c->ecount1 - 1;
                            ac = oc;
                            bc = c;
                            break;
                        }
                    }
                }
            }
        }

        if (bc != null)
        {
            return res(ac, bc);
        }
    }

    return "0 0 0 0\n";
}

int main(int argc, char* args[])
{
    printf(go(args[1]).c_str());
    return 0;
}