战舰!

早在2003年(当时我17岁),我参加了一场《战舰》AI编码比赛。尽管我输了那场比赛,但我从中获得了很多乐趣,也学到了很多东西。

现在,我想恢复这个比赛,在搜索最好的战舰AI。

下面是这个框架,现在托管在Bitbucket上。

获胜者将获得+450声望奖励!比赛将于2009年11月17日开始。17号零时之前的投稿和编辑将不被接受。(中央标准时间) 尽早提交你的作品,这样你就不会错过机会!

为了保持这个目标,请遵循比赛的精神。

游戏规则:

游戏在10x10的网格上进行。 每个参赛者将5艘船(长度为2、3、3、4、5)中的每一艘放在他们的网格上。 没有船只可以重叠,但它们可以相邻。 然后选手们轮流向对手射击。 游戏的一个变体允许每次齐射多次,每艘幸存的船一次。 如果击球沉、命中或未命中,对手将通知选手。 当任何一名玩家的所有船只都沉没时,游戏就结束了。

比赛规则:

The spirit of the competition is to find the best Battleship algorithm. Anything that is deemed against the spirit of the competition will be grounds for disqualification. Interfering with an opponent is against the spirit of the competition. Multithreading may be used under the following restrictions: No more than one thread may be running while it is not your turn. (Though, any number of threads may be in a "Suspended" state). No thread may run at a priority other than "Normal". Given the above two restrictions, you will be guaranteed at least 3 dedicated CPU cores during your turn. A limit of 1 second of CPU time per game is allotted to each competitor on the primary thread. Running out of time results in losing the current game. Any unhandled exception will result in losing the current game. Network access and disk access is allowed, but you may find the time restrictions fairly prohibitive. However, a few set-up and tear-down methods have been added to alleviate the time strain. Code should be posted on stack overflow as an answer, or, if too large, linked. Max total size (un-compressed) of an entry is 1 MB. Officially, .Net 2.0 / 3.5 is the only framework requirement. Your entry must implement the IBattleshipOpponent interface.

得分:

Best 51 games out of 101 games is the winner of a match. All competitors will play matched against each other, round-robin style. The best half of the competitors will then play a double-elimination tournament to determine the winner. (Smallest power of two that is greater than or equal to half, actually.) I will be using the TournamentApi framework for the tournament. The results will be posted here. If you submit more than one entry, only your best-scoring entry is eligible for the double-elim.

好运!玩得开心!


编辑1: 多亏弗里德,他在飞船上发现了一个错误。是否是可用的函数。问题已经解决了。请下载框架的更新版本。

编辑2: 由于人们对将统计数据持久化到磁盘等非常感兴趣,所以我添加了一些非计时设置和删除事件,它们应该能够提供所需的功能。这是一个半突破性的变化。也就是说:修改了接口,添加了功能,但不需要body。请下载框架的更新版本。

编辑3: 错误修复1:GameWon和GameLost只在超时的情况下被调用。 错误修复2:如果引擎在每一款游戏中都暂停计时,那么竞争将永远不会结束。 请下载框架的更新版本。

编辑4: 比赛结果:


当前回答

这是一个供人们玩的对手:

http://natekohl.net/files/FarnsworthOpponent.cs

与其使用固定的几何启发策略,我认为尝试估计任何特定的未探索空间拥有一艘船的潜在概率会很有趣。

为了做到这一点,你需要探索所有符合你当前世界观的船的可能配置,然后基于这些配置计算概率。你可以把它想象成探索一棵树:

扩大可能的战列舰国家http://natekohl.net/media/battleship-tree.png

在考虑了所有与你所了解的世界相冲突的树叶后(游戏邦注:例如,船只不能重叠,所有被击中的方块都必须是船只等),你可以计算船只在每个未探索位置出现的频率,从而估算船只位于那里的可能性。

这可以可视化为热图,其中热点更有可能包含船只:

每个未开发位置的概率热图http://natekohl.net/media/battleship-probs.png

我喜欢这个战列舰比赛的一个原因是上面的树几乎小到可以强制使用这种算法。如果这5艘船每艘都有150个可能的位置,那就是1505 = 750亿种可能性。这个数字只会越来越小,特别是如果你可以排除整艘船。

我上面链接的对手并没有探索整棵树;750亿美元仍然太大,无法在一秒钟内进入。不过,在一些启发式的帮助下,它确实试图估计这些概率。

其他回答

我预测,能够逆向设计对手随机种子和呼叫模式的人将获胜。

但不确定这种可能性有多大。

我总是喜欢从中间开始,从那个点螺旋离开,在任何其他点之间留下不超过1个空白,以解释那个该死的子…射击间隔取决于哪艘船被击沉。如果b舰是最后一艘,射击之间只需要留出4个空间来减少浪费

事实上,这个解决方案在ubuntu 9.10 linux的monodevelop中无需修改就可以打开和运行

我的电脑现在正在戴尔维修,但这是我上周在哪里:

namespace Battleship
{
    using System;
    using System.Collections.ObjectModel;
    using System.Drawing;
    using System.Collections.Generic;
    using System.Linq;

    public class BSKiller4 : OpponentExtended, IBattleshipOpponent
    {
        public string Name { get { return "BSKiller4"; } }
        public Version Version { get { return this.version; } }

        public bool showBoard = false;

        Random rand = new Random();
        Version version = new Version(0, 4);
        Size gameSize;

        List<Point> nextShots;
        Queue<Point> scanShots;

        char[,] board;

        private void printBoard()
        {
            Console.WriteLine();
            for (int y = 0; y < this.gameSize.Height; y++)
            {
                for (int x = 0; x < this.gameSize.Width; x++)
                {
                    Console.Write(this.board[x, y]);
                }
                Console.WriteLine();
            }
            Console.ReadKey();
        }

        public void NewGame(Size size, TimeSpan timeSpan)
        {
            this.gameSize = size;
            board = new char[size.Width, size.Height];
            this.nextShots = new List<Point>();
            this.scanShots = new Queue<Point>();
            fillScanShots();
            initializeBoard();
        }

        private void initializeBoard()
        {
            for (int y = 0; y < this.gameSize.Height; y++)
            {
                for (int x = 0; x < this.gameSize.Width; x++)
                {
                    this.board[x, y] = 'O';
                }
            }
        }

        private void fillScanShots()
        {
            int x, y;
            int num = gameSize.Width * gameSize.Height;
            for (int j = 0; j < 3; j++)
            {
                for (int i = j; i < num; i += 3)
                {
                    x = i % gameSize.Width;
                    y = i / gameSize.Height;
                    scanShots.Enqueue(new Point(x, y));
                }
            }
        }

        public void PlaceShips(ReadOnlyCollection<Ship> ships)
        {
            foreach (Ship s in ships)
            {
                s.Place(new Point(
                        rand.Next(this.gameSize.Width),
                        rand.Next(this.gameSize.Height)),
                        (ShipOrientation)rand.Next(2));
            }
        }

        public Point GetShot()
        {
            if (showBoard) printBoard();
            Point shot;

            shot = findShotRun();
            if (shot.X != -1)
            {
                return shot;
            }

            if (this.nextShots.Count > 0)
            {
                shot = this.nextShots[0];
                this.nextShots.RemoveAt(0);
            }
            else
            {
                shot = this.scanShots.Dequeue();
            }

            return shot;
        }

        public void ShotHit(Point shot, bool sunk)
        {
            this.board[shot.X, shot.Y] = 'H';
            if (!sunk)
            {
                addToNextShots(new Point(shot.X - 1, shot.Y));
                addToNextShots(new Point(shot.X, shot.Y + 1));
                addToNextShots(new Point(shot.X + 1, shot.Y));
                addToNextShots(new Point(shot.X, shot.Y - 1));
            }
            else
            {
                this.nextShots.Clear();
            }
        }



        private Point findShotRun()
        {
            int run_forward_horizontal = 0;
            int run_backward_horizontal = 0;
            int run_forward_vertical = 0;
            int run_backward_vertical = 0;

            List<shotPossibilities> possible = new List<shotPossibilities>(5);

            // this only works if width = height for the board;
            for (int y = 0; y < this.gameSize.Height; y++)
            {
                for (int x = 0; x < this.gameSize.Width; x++)
                {
                    // forward horiz
                    if (this.board[x, y] == 'M')
                    {
                        run_forward_horizontal = 0;
                    }
                    else if (this.board[x, y] == 'O')
                    {
                        if (run_forward_horizontal >= 2)
                        {
                            possible.Add(
                                new shotPossibilities(
                                    run_forward_horizontal,
                                    new Point(x, y),
                                    true));
                        }
                        else
                        {
                            run_forward_horizontal = 0;
                        }
                    }
                    else
                    {
                        run_forward_horizontal++;
                    }

                    // forward vertical
                    if (this.board[y, x] == 'M')
                    {
                        run_forward_vertical = 0;
                    }
                    else if (this.board[y, x] == 'O')
                    {
                        if (run_forward_vertical >= 2)
                        {
                            possible.Add(
                                new shotPossibilities(
                                    run_forward_vertical,
                                    new Point(y, x),
                                    false));
                        }
                        else
                        {
                            run_forward_vertical = 0;
                        }
                    }
                    else
                    {
                        run_forward_vertical++;
                    }


                    // backward horiz
                    if (this.board[this.gameSize.Width - x - 1, y] == 'M')
                    {
                        run_backward_horizontal = 0;
                    }
                    else if (this.board[this.gameSize.Width - x - 1, y] == 'O')
                    {
                        if (run_backward_horizontal >= 2)
                        {
                            possible.Add(
                                new shotPossibilities(
                                    run_backward_horizontal,
                                    new Point(this.gameSize.Width - x - 1, y),
                                    true));
                        }
                        else
                        {
                            run_backward_horizontal = 0;
                        }
                    }
                    else
                    {
                        run_backward_horizontal++;
                    }


                    // backward vertical
                    if (this.board[y, this.gameSize.Height - x - 1] == 'M')
                    {
                        run_backward_vertical = 0;
                    }
                    else if (this.board[y, this.gameSize.Height - x - 1] == 'O')
                    {
                        if (run_backward_vertical >= 2)
                        {
                            possible.Add(
                                new shotPossibilities(
                                    run_backward_vertical,
                                    new Point(y, this.gameSize.Height - x - 1),
                                    false));
                        }
                        else
                        {
                            run_backward_vertical = 0;
                        }
                    }
                    else
                    {
                        run_backward_vertical++;
                    }

                }

                run_forward_horizontal = 0;
                run_backward_horizontal = 0;
                run_forward_vertical = 0;
                run_backward_vertical = 0;
            }
            Point shot;

            if (possible.Count > 0)
            {
                shotPossibilities shotp = possible.OrderByDescending(a => a.run).First();
                //this.nextShots.Clear();
                shot = shotp.shot;
                //if (shotp.isHorizontal)
                //{
                //    this.nextShots.RemoveAll(p => p.X != shot.X);
                //}
                //else
                //{
                //    this.nextShots.RemoveAll(p => p.Y != shot.Y);
                //}
            }
            else
            {
                shot = new Point(-1, -1);
            }

            return shot;
        }

        private void addToNextShots(Point p)
        {
            if (!this.nextShots.Contains(p) &&
                p.X >= 0 &&
                p.X < this.gameSize.Width &&
                p.Y >= 0 &&
                p.Y < this.gameSize.Height)
            {
                if (this.board[p.X, p.Y] == 'O')
                {
                    this.nextShots.Add(p);
                }
            }
        }

        public void GameWon()
        {
            this.GameWins++;
        }

        public void NewMatch(string opponent)
        {
            System.Threading.Thread.Sleep(5);
            this.rand = new Random(System.Environment.TickCount);
        }
        public void OpponentShot(Point shot) { }
        public void ShotMiss(Point shot)
        {
            this.board[shot.X, shot.Y] = 'M';
        }
        public void GameLost()
        {
            if (showBoard) Console.WriteLine("-----Game Over-----");
        }
        public void MatchOver() { }
    }


    public class OpponentExtended
    {
        public int GameWins { get; set; }
        public int MatchWins { get; set; }
        public OpponentExtended() { }
    }

    public class shotPossibilities
    {
        public shotPossibilities(int r, Point s, bool h)
        {
            this.run = r;
            this.shot = s;
            this.isHorizontal = h;
        }
        public int run { get; set; }
        public Point shot { get; set; }
        public bool isHorizontal { get; set; }
    }
}

交火中更新。 我知道它不能与Farnsworth或Dreadnought竞争,但它比后者快得多,而且如果有人想尝试的话,它很简单。 这依赖于我的库的当前状态,包括在这里使它易于使用。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.IO;
using System.Collections.ObjectModel;

namespace Battleship.ShuggyCoUk
{
    public class Simple : IBattleshipOpponent
    {
        BoardView<OpponentsBoardState> opponentsBoard = new BoardView<OpponentsBoardState>(new Size(10,10));
        Rand rand = new Rand();
        int gridOddEven;
        Size size;

        public string Name { get { return "Simple"; } }

        public Version Version { get { return new Version(2, 1); }}

        public void NewMatch(string opponent) {}

        public void NewGame(System.Drawing.Size size, TimeSpan timeSpan)
        {
            this.size = size;
            this.opponentsBoard = new BoardView<OpponentsBoardState>(size);
            this.gridOddEven = rand.Pick(new[] { 0, 1 });
        }

        public void PlaceShips(System.Collections.ObjectModel.ReadOnlyCollection<Ship> ships)
        {
            BoardView<bool> board = new BoardView<bool>(size);
            var AllOrientations = new[] {
                ShipOrientation.Horizontal,
                ShipOrientation.Vertical };

            foreach (var ship in ships)
            {
                int avoidTouching = 3;
                while (!ship.IsPlaced)
                {
                    var l = rand.Pick(board.Select(c => c.Location));
                    var o = rand.Pick(AllOrientations);
                    if (ship.IsLegal(ships, size, l, o))
                    {
                        if (ship.IsTouching(ships, l, o)&& --avoidTouching > 0)
                            continue;
                        ship.Place(l, o);
                    }
                }
            }
        }
        protected virtual Point PickWhenNoTargets()
        {
            return rand.PickBias(x => x.Bias,
                opponentsBoard
                // nothing 1 in size
                .Where(c => (c.Location.X + c.Location.Y) % 2 == gridOddEven)
                .Where(c => c.Data == OpponentsBoardState.Unknown))
                .Location;
        }

        private int SumLine(Cell<OpponentsBoardState> c, int acc)
        {
            if (acc >= 0)
                return acc;
            if (c.Data == OpponentsBoardState.Hit)
                return acc - 1;
            return -acc;
        }

        public System.Drawing.Point GetShot()
        {
            var targets = opponentsBoard
                .Where(c => c.Data == OpponentsBoardState.Hit)
                .SelectMany(c => c.Neighbours())
                .Where(c => c.Data == OpponentsBoardState.Unknown)
                .ToList();
            if (targets.Count > 1)
            {
                var lines = targets.Where(
                    x => x.FoldAll(-1, SumLine).Select(r => Math.Abs(r) - 1).Max() > 1).ToList();
                if (lines.Count > 0)
                    targets = lines;
            }
            var target = targets.RandomOrDefault(rand);
            if (target == null)
                return PickWhenNoTargets();
            return target.Location;
        }

        public void OpponentShot(System.Drawing.Point shot)
        {
        }

        public void ShotHit(Point shot, bool sunk)
        {
            opponentsBoard[shot] = OpponentsBoardState.Hit;
            Debug(shot, sunk);
        }

        public void ShotMiss(Point shot)
        {
            opponentsBoard[shot] = OpponentsBoardState.Miss;
            Debug(shot, false);
        }

        public const bool DebugEnabled = false;

        public void Debug(Point shot, bool sunk)
        {
            if (!DebugEnabled)
                return;
            opponentsBoard.WriteAsGrid(
                Console.Out,
                x =>
                {
                    string t;
                    switch (x.Data)
                    {
                        case OpponentsBoardState.Unknown:
                            return " ";
                        case OpponentsBoardState.Miss:
                            t = "m";
                            break;
                        case OpponentsBoardState.MustBeEmpty:
                            t = "/";
                            break;
                        case OpponentsBoardState.Hit:
                            t = "x";
                            break;
                        default:
                            t = "?";
                            break;
                    }
                    if (x.Location == shot)
                        t = t.ToUpper();
                    return t;
                });
            if (sunk)
                Console.WriteLine("sunk!");
            Console.ReadLine();
        }

        public void GameWon()
        {
        }

        public void GameLost()
        {
        }

        public void MatchOver()
        {
        }

        #region Library code
        enum OpponentsBoardState
        {
            Unknown = 0,
            Miss,
            MustBeEmpty,
            Hit,
        }

        public enum Compass
        {
            North, East, South, West
        }

        class Cell<T>
        {
            private readonly BoardView<T> view;
            public readonly int X;
            public readonly int Y;
            public T Data;
            public double Bias { get; set; }

            public Cell(BoardView<T> view, int x, int y)
            {
                this.view = view; this.X = x; this.Y = y; this.Bias = 1.0;
            }

            public Point Location
            {
                get { return new Point(X, Y); }
            }

            public IEnumerable<U> FoldAll<U>(U acc, Func<Cell<T>, U, U> trip)
            {
                return new[] { Compass.North, Compass.East, Compass.South, Compass.West }
                    .Select(x => FoldLine(x, acc, trip));
            }

            public U FoldLine<U>(Compass direction, U acc, Func<Cell<T>, U, U> trip)
            {
                var cell = this;
                while (true)
                {
                    switch (direction)
                    {
                        case Compass.North:
                            cell = cell.North; break;
                        case Compass.East:
                            cell = cell.East; break;
                        case Compass.South:
                            cell = cell.South; break;
                        case Compass.West:
                            cell = cell.West; break;
                    }
                    if (cell == null)
                        return acc;
                    acc = trip(cell, acc);
                }
            }

            public Cell<T> North
            {
                get { return view.SafeLookup(X, Y - 1); }
            }

            public Cell<T> South
            {
                get { return view.SafeLookup(X, Y + 1); }
            }

            public Cell<T> East
            {
                get { return view.SafeLookup(X + 1, Y); }
            }

            public Cell<T> West
            {
                get { return view.SafeLookup(X - 1, Y); }
            }

            public IEnumerable<Cell<T>> Neighbours()
            {
                if (North != null)
                    yield return North;
                if (South != null)
                    yield return South;
                if (East != null)
                    yield return East;
                if (West != null)
                    yield return West;
            }
        }

        class BoardView<T> : IEnumerable<Cell<T>>
        {
            public readonly Size Size;
            private readonly int Columns;
            private readonly int Rows;

            private Cell<T>[] history;

            public BoardView(Size size)
            {
                this.Size = size;
                Columns = size.Width;
                Rows = size.Height;
                this.history = new Cell<T>[Columns * Rows];
                for (int y = 0; y < Rows; y++)
                {
                    for (int x = 0; x < Rows; x++)
                        history[x + y * Columns] = new Cell<T>(this, x, y);
                }
            }

            public T this[int x, int y]
            {
                get { return history[x + y * Columns].Data; }
                set { history[x + y * Columns].Data = value; }
            }

            public T this[Point p]
            {
                get { return history[SafeCalc(p.X, p.Y, true)].Data; }
                set { this.history[SafeCalc(p.X, p.Y, true)].Data = value; }
            }

            private int SafeCalc(int x, int y, bool throwIfIllegal)
            {
                if (x < 0 || y < 0 || x >= Columns || y >= Rows)
                {
                    if (throwIfIllegal)
                        throw new ArgumentOutOfRangeException("[" + x + "," + y + "]");
                    else
                        return -1;
                }
                return x + y * Columns;
            }

            public void Set(T data)
            {
                foreach (var cell in this.history)
                    cell.Data = data;
            }

            public Cell<T> SafeLookup(int x, int y)
            {
                int index = SafeCalc(x, y, false);
                if (index < 0)
                    return null;
                return history[index];
            }

            #region IEnumerable<Cell<T>> Members

            public IEnumerator<Cell<T>> GetEnumerator()
            {
                foreach (var cell in this.history)
                    yield return cell;
            }

            System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
            {
                return this.GetEnumerator();
            }

            public BoardView<U> Transform<U>(Func<T, U> transform)
            {
                var result = new BoardView<U>(new Size(Columns, Rows));
                for (int y = 0; y < Rows; y++)
                {
                    for (int x = 0; x < Columns; x++)
                    {
                        result[x, y] = transform(this[x, y]);
                    }
                }
                return result;
            }

            public void WriteAsGrid(TextWriter w)
            {
                WriteAsGrid(w, "{0}");
            }

            public void WriteAsGrid(TextWriter w, string format)
            {
                WriteAsGrid(w, x => string.Format(format, x.Data));
            }

            public void WriteAsGrid(TextWriter w, Func<Cell<T>, string> perCell)
            {
                for (int y = 0; y < Rows; y++)
                {
                    for (int x = 0; x < Columns; x++)
                    {
                        if (x != 0)
                            w.Write(",");
                        w.Write(perCell(this.SafeLookup(x, y)));
                    }
                    w.WriteLine();
                }
            }

            #endregion
        }

        public class Rand
        {
            Random r;

            public Rand()
            {
                var rand = System.Security.Cryptography.RandomNumberGenerator.Create();
                byte[] b = new byte[4];
                rand.GetBytes(b);
                r = new Random(BitConverter.ToInt32(b, 0));
            }

            public int Next(int maxValue)
            {
                return r.Next(maxValue);
            }

            public double NextDouble(double maxValue)
            {
                return r.NextDouble() * maxValue;
            }

            public T Pick<T>(IEnumerable<T> things)
            {
                return things.ElementAt(Next(things.Count()));
            }

            public T PickBias<T>(Func<T, double> bias, IEnumerable<T> things)
            {
                double d = NextDouble(things.Sum(x => bias(x)));
                foreach (var x in things)
                {
                    if (d < bias(x))
                        return x;
                    d -= bias(x);
                }
                throw new InvalidOperationException("fell off the end!");
            }
        }
        #endregion
    }

    public static class Extensions
    {
        public static bool IsIn(this Point p, Size size)
        {
            return p.X >= 0 && p.Y >= 0 && p.X < size.Width && p.Y < size.Height;
        }

        public static bool IsLegal(this Ship ship,
            IEnumerable<Ship> ships,
            Size board,
            Point location,
            ShipOrientation direction)
        {
            var temp = new Ship(ship.Length);
            temp.Place(location, direction);
            if (!temp.GetAllLocations().All(p => p.IsIn(board)))
                return false;
            return ships.Where(s => s.IsPlaced).All(s => !s.ConflictsWith(temp));
        }

        public static bool IsTouching(this Point a, Point b)
        {
            return (a.X == b.X - 1 || a.X == b.X + 1) &&
                (a.Y == b.Y - 1 || a.Y == b.Y + 1);
        }

        public static bool IsTouching(this Ship ship,
            IEnumerable<Ship> ships,
            Point location,
            ShipOrientation direction)
        {
            var temp = new Ship(ship.Length);
            temp.Place(location, direction);
            var occupied = new HashSet<Point>(ships
                .Where(s => s.IsPlaced)
                .SelectMany(s => s.GetAllLocations()));
            if (temp.GetAllLocations().Any(p => occupied.Any(b => b.IsTouching(p))))
                return true;
            return false;
        }

        public static ReadOnlyCollection<Ship> MakeShips(params int[] lengths)
        {
            return new System.Collections.ObjectModel.ReadOnlyCollection<Ship>(
                lengths.Select(l => new Ship(l)).ToList());
        }

        public static IEnumerable<T> Shuffle<T>(this IEnumerable<T> source, Battleship.ShuggyCoUk.Simple.Rand rand)
        {
            T[] elements = source.ToArray();
            // Note i > 0 to avoid final pointless iteration
            for (int i = elements.Length - 1; i > 0; i--)
            {
                // Swap element "i" with a random earlier element it (or itself)
                int swapIndex = rand.Next(i + 1);
                T tmp = elements[i];
                elements[i] = elements[swapIndex];
                elements[swapIndex] = tmp;
            }
            // Lazily yield (avoiding aliasing issues etc)
            foreach (T element in elements)
            {
                yield return element;
            }
        }

        public static T RandomOrDefault<T>(this IEnumerable<T> things, Battleship.ShuggyCoUk.Simple.Rand rand)
        {
            int count = things.Count();
            if (count == 0)
                return default(T);
            return things.ElementAt(rand.Next(count));
        }
    }

}