最近我一直在iPhone上玩一款名为《Scramble》的游戏。有些人可能知道这个游戏叫拼字游戏。从本质上讲,当游戏开始时,你会得到一个字母矩阵:

F X I E
A M L O
E W B X
A S T U

The goal of the game is to find as many words as you can that can be formed by chaining letters together. You can start with any letter, and all the letters that surround it are fair game, and then once you move on to the next letter, all the letters that surround that letter are fair game, except for any previously used letters. So in the grid above, for example, I could come up with the words LOB, TUX, SEA, FAME, etc. Words must be at least 3 characters, and no more than NxN characters, which would be 16 in this game but can vary in some implementations. While this game is fun and addictive, I am apparently not very good at it and I wanted to cheat a little bit by making a program that would give me the best possible words (the longer the word the more points you get).

(来源:boggled.org)

不幸的是,我不太擅长算法或它们的效率等等。我的第一次尝试使用一个像这样的字典(约2.3MB),并进行线性搜索,试图匹配字典条目的组合。这需要花费很长时间来找到可能的单词,因为你每轮只有2分钟的时间,这是不够的。

我很有兴趣看看是否有任何Stackoverflowers可以提出更有效的解决方案。我主要是在寻找使用三大p的解决方案:Python、PHP和Perl,尽管任何使用Java或c++的东西也很酷,因为速度是至关重要的。

目前的解决方案:

Adam Rosenfield, Python, ~20岁 John Fouhy, Python, ~3秒 Kent Fredric, Perl, ~1s Darius Bacon, Python, ~1s rvarcher, VB。净,~ 1 s Paolo Bergantino, PHP(实时链接),~5s(本地~2s)


当前回答

令人惊讶的是,没有人尝试使用PHP版本。

这是John Fouhy的Python解决方案的PHP版本。

虽然我从其他人的答案中得到了一些建议,但这主要是抄袭约翰的。

$boggle = "fxie
           amlo
           ewbx
           astu";

$alphabet = str_split(str_replace(array("\n", " ", "\r"), "", strtolower($boggle)));
$rows = array_map('trim', explode("\n", $boggle));
$dictionary = file("C:/dict.txt");
$prefixes = array(''=>'');
$words = array();
$regex = '/[' . implode('', $alphabet) . ']{3,}$/S';
foreach($dictionary as $k=>$value) {
    $value = trim(strtolower($value));
    $length = strlen($value);
    if(preg_match($regex, $value)) {
        for($x = 0; $x < $length; $x++) {
            $letter = substr($value, 0, $x+1);
            if($letter == $value) {
                $words[$value] = 1;
            } else {
                $prefixes[$letter] = 1;
            }
        }
    }
}

$graph = array();
$chardict = array();
$positions = array();
$c = count($rows);
for($i = 0; $i < $c; $i++) {
    $l = strlen($rows[$i]);
    for($j = 0; $j < $l; $j++) {
        $chardict[$i.','.$j] = $rows[$i][$j];
        $children = array();
        $pos = array(-1,0,1);
        foreach($pos as $z) {
            $xCoord = $z + $i;
            if($xCoord < 0 || $xCoord >= count($rows)) {
                continue;
            }
            $len = strlen($rows[0]);
            foreach($pos as $w) {
                $yCoord = $j + $w;
                if(($yCoord < 0 || $yCoord >= $len) || ($z == 0 && $w == 0)) {
                    continue;
                }
                $children[] = array($xCoord, $yCoord);
            }
        }
        $graph['None'][] = array($i, $j);
        $graph[$i.','.$j] = $children;
    }
}

function to_word($chardict, $prefix) {
    $word = array();
    foreach($prefix as $v) {
        $word[] = $chardict[$v[0].','.$v[1]];
    }
    return implode("", $word);
}

function find_words($graph, $chardict, $position, $prefix, $prefixes, &$results, $words) {
    $word = to_word($chardict, $prefix);
    if(!isset($prefixes[$word])) return false;

    if(isset($words[$word])) {
        $results[] = $word;
    }

    foreach($graph[$position] as $child) {
        if(!in_array($child, $prefix)) {
            $newprefix = $prefix;
            $newprefix[] = $child;
            find_words($graph, $chardict, $child[0].','.$child[1], $newprefix, $prefixes, $results, $words);
        }
    }
}

$solution = array();
find_words($graph, $chardict, 'None', array(), $prefixes, $solution);
print_r($solution);

如果你想尝试的话,这里有一个实时链接。虽然在我的本地机器上需要大约2秒,但在我的web服务器上需要大约5秒。无论哪种情况,它都不是很快。尽管如此,它还是很可怕,所以我可以想象时间可以大大缩短。任何关于如何实现这一目标的建议都将不胜感激。PHP缺少元组,这使得坐标处理起来很奇怪,而且我无法理解到底发生了什么,这对我一点帮助都没有。

编辑:一些修复使它在本地少于1秒。

其他回答

我很快完美地解决了这个问题。我把它放进了一个安卓应用程序。在play store链接中查看视频,看看它是如何运作的。

单词作弊是一个应用程序,“破解”任何矩阵风格的文字游戏。这个应用程序 来帮我在文字混淆器上作弊。它可以用于单词搜索, 沙沙,单词,单词查找器,单词破解,拼字游戏,和更多!

在这里可以看到 https://play.google.com/store/apps/details?id=com.harris.wordcracker

在视频中查看应用程序的操作 https://www.youtube.com/watch?v=DL2974WmNAI

你可以把这个问题分成两部分:

某种搜索算法可以在网格中列举出可能的字符串。 一种测试字符串是否是有效单词的方法。

理想情况下,(2)还应该包括一种测试字符串是否是有效单词前缀的方法——这将允许您精简搜索并节省大量时间。

亚当·罗森菲尔德(Adam Rosenfield)的Trie是(2)的一个解决方案。它很优雅,可能是算法专家的首选,但有了现代语言和现代计算机,我们可能会更懒一点。此外,正如Kent所建议的,我们可以通过丢弃网格中没有字母的单词来减少字典的大小。这是一些蟒蛇:

def make_lookups(grid, fn='dict.txt'):
    # Make set of valid characters.
    chars = set()
    for word in grid:
        chars.update(word)

    words = set(x.strip() for x in open(fn) if set(x.strip()) <= chars)
    prefixes = set()
    for w in words:
        for i in range(len(w)+1):
            prefixes.add(w[:i])

    return words, prefixes

哇;常数时间前缀测试。加载你链接的字典需要几秒钟,但只有几秒钟:-)(注意words <= prefixes)

现在,对于第(1)部分,我倾向于用图表来思考。所以我将创建一个像这样的字典:

graph = { (x, y):set([(x0,y0), (x1,y1), (x2,y2)]), }

例如,graph[(x, y)]是你从位置(x, y)可以到达的坐标集。我还将添加一个虚拟节点None,它将连接到所有东西。

构建它有点笨拙,因为有8个可能的位置,你必须做边界检查。下面是一些相应笨拙的python代码:

def make_graph(grid):
    root = None
    graph = { root:set() }
    chardict = { root:'' }

    for i, row in enumerate(grid):
        for j, char in enumerate(row):
            chardict[(i, j)] = char
            node = (i, j)
            children = set()
            graph[node] = children
            graph[root].add(node)
            add_children(node, children, grid)

    return graph, chardict

def add_children(node, children, grid):
    x0, y0 = node
    for i in [-1,0,1]:
        x = x0 + i
        if not (0 <= x < len(grid)):
            continue
        for j in [-1,0,1]:
            y = y0 + j
            if not (0 <= y < len(grid[0])) or (i == j == 0):
                continue

            children.add((x,y))

这段代码还建立了一个字典映射(x,y)到相应的字符。这让我把一个位置列表转换成一个单词:

def to_word(chardict, pos_list):
    return ''.join(chardict[x] for x in pos_list)

最后,我们进行深度优先搜索。基本程序是:

搜索到达一个特定的节点。 检查到目前为止的路径是否可能是单词的一部分。如果不是,就不要进一步探索这个分支。 检查到目前为止的路径是否是一个单词。如果是,则添加到结果列表中。 探索迄今为止所有孩子未走的路。

Python:

def find_words(graph, chardict, position, prefix, results, words, prefixes):
    """ Arguments:
      graph :: mapping (x,y) to set of reachable positions
      chardict :: mapping (x,y) to character
      position :: current position (x,y) -- equals prefix[-1]
      prefix :: list of positions in current string
      results :: set of words found
      words :: set of valid words in the dictionary
      prefixes :: set of valid words or prefixes thereof
    """
    word = to_word(chardict, prefix)

    if word not in prefixes:
        return

    if word in words:
        results.add(word)

    for child in graph[position]:
        if child not in prefix:
            find_words(graph, chardict, child, prefix+[child], results, words, prefixes)

运行代码如下:

grid = ['fxie', 'amlo', 'ewbx', 'astu']
g, c = make_graph(grid)
w, p = make_lookups(grid)
res = set()
find_words(g, c, None, [], res, w, p)

检查保留区,看看答案。下面是为你的例子找到的单词列表,按大小排序:

 ['a', 'b', 'e', 'f', 'i', 'l', 'm', 'o', 's', 't',
 'u', 'w', 'x', 'ae', 'am', 'as', 'aw', 'ax', 'bo',
 'bu', 'ea', 'el', 'em', 'es', 'fa', 'ie', 'io', 'li',
 'lo', 'ma', 'me', 'mi', 'oe', 'ox', 'sa', 'se', 'st',
 'tu', 'ut', 'wa', 'we', 'xi', 'aes', 'ame', 'ami',
 'ase', 'ast', 'awa', 'awe', 'awl', 'blo', 'but', 'elb',
 'elm', 'fae', 'fam', 'lei', 'lie', 'lim', 'lob', 'lox',
 'mae', 'maw', 'mew', 'mil', 'mix', 'oil', 'olm', 'saw',
 'sea', 'sew', 'swa', 'tub', 'tux', 'twa', 'wae', 'was',
 'wax', 'wem', 'ambo', 'amil', 'amli', 'asem', 'axil',
 'axle', 'bleo', 'boil', 'bole', 'east', 'fame', 'limb',
 'lime', 'mesa', 'mewl', 'mile', 'milo', 'oime', 'sawt',
 'seam', 'seax', 'semi', 'stub', 'swam', 'twae', 'twas',
 'wame', 'wase', 'wast', 'weam', 'west', 'amble', 'awest',
 'axile', 'embox', 'limbo', 'limes', 'swami', 'embole',
 'famble', 'semble', 'wamble']

代码需要(字面上的)几秒钟来加载字典,但其余的在我的机器上是立即完成的。

一个Node.JS JavaScript解决方案。在不到一秒钟的时间内计算所有100个独特的单词,其中包括阅读字典文件(MBA 2012)。

Output: ["FAM","TUX","TUB","FAE","ELI","ELM","ELB","TWA","TWA","SAW","AMI","SWA","SWA","AME","SEA","SEW","AES","AWL","AWE","SEA","AWA","MIX","MIL","AST","ASE","MAX","MAE","MAW","MEW","AWE","MES","AWL","LIE","LIM","AWA","AES","BUT","BLO","WAS","WAE","WEA","LEI","LEO","LOB","LOX","WEM","OIL","OLM","WEA","WAE","WAX","WAF","MILO","EAST","WAME","TWAS","TWAE","EMIL","WEAM","OIME","AXIL","WEST","TWAE","LIMB","WASE","WAST","BLEO","STUB","BOIL","BOLE","LIME","SAWT","LIMA","MESA","MEWL","AXLE","FAME","ASEM","MILE","AMIL","SEAX","SEAM","SEMI","SWAM","AMBO","AMLI","AXILE","AMBLE","SWAMI","AWEST","AWEST","LIMAX","LIMES","LIMBU","LIMBO","EMBOX","SEMBLE","EMBOLE","WAMBLE","FAMBLE"]

代码:

var fs = require('fs')

var Node = function(value, row, col) {
    this.value = value
    this.row = row
    this.col = col
}

var Path = function() {
    this.nodes = []
}

Path.prototype.push = function(node) {
    this.nodes.push(node)
    return this
}

Path.prototype.contains = function(node) {
    for (var i = 0, ii = this.nodes.length; i < ii; i++) {
        if (this.nodes[i] === node) {
            return true
        }
    }

    return false
}

Path.prototype.clone = function() {
    var path = new Path()
    path.nodes = this.nodes.slice(0)
    return path
}

Path.prototype.to_word = function() {
    var word = ''

    for (var i = 0, ii = this.nodes.length; i < ii; ++i) {
        word += this.nodes[i].value
    }

    return word
}

var Board = function(nodes, dict) {
    // Expects n x m array.
    this.nodes = nodes
    this.words = []
    this.row_count = nodes.length
    this.col_count = nodes[0].length
    this.dict = dict
}

Board.from_raw = function(board, dict) {
    var ROW_COUNT = board.length
      , COL_COUNT = board[0].length

    var nodes = []

    // Replace board with Nodes
    for (var i = 0, ii = ROW_COUNT; i < ii; ++i) {
        nodes.push([])
        for (var j = 0, jj = COL_COUNT; j < jj; ++j) {
            nodes[i].push(new Node(board[i][j], i, j))
        }
    }

    return new Board(nodes, dict)
}

Board.prototype.toString = function() {
    return JSON.stringify(this.nodes)
}

Board.prototype.update_potential_words = function(dict) {
    for (var i = 0, ii = this.row_count; i < ii; ++i) {
        for (var j = 0, jj = this.col_count; j < jj; ++j) {
            var node = this.nodes[i][j]
              , path = new Path()

            path.push(node)

            this.dfs_search(path)
        }
    }
}

Board.prototype.on_board = function(row, col) {
    return 0 <= row && row < this.row_count && 0 <= col && col < this.col_count
}

Board.prototype.get_unsearched_neighbours = function(path) {
    var last_node = path.nodes[path.nodes.length - 1]

    var offsets = [
        [-1, -1], [-1,  0], [-1, +1]
      , [ 0, -1],           [ 0, +1]
      , [+1, -1], [+1,  0], [+1, +1]
    ]

    var neighbours = []

    for (var i = 0, ii = offsets.length; i < ii; ++i) {
        var offset = offsets[i]
        if (this.on_board(last_node.row + offset[0], last_node.col + offset[1])) {

            var potential_node = this.nodes[last_node.row + offset[0]][last_node.col + offset[1]]
            if (!path.contains(potential_node)) {
                // Create a new path if on board and we haven't visited this node yet.
                neighbours.push(potential_node)
            }
        }
    }

    return neighbours
}

Board.prototype.dfs_search = function(path) {
    var path_word = path.to_word()

    if (this.dict.contains_exact(path_word) && path_word.length >= 3) {
        this.words.push(path_word)
    }

    var neighbours = this.get_unsearched_neighbours(path)

    for (var i = 0, ii = neighbours.length; i < ii; ++i) {
        var neighbour = neighbours[i]
        var new_path = path.clone()
        new_path.push(neighbour)

        if (this.dict.contains_prefix(new_path.to_word())) {
            this.dfs_search(new_path)
        }
    }
}

var Dict = function() {
    this.dict_array = []

    var dict_data = fs.readFileSync('./web2', 'utf8')
    var dict_array = dict_data.split('\n')

    for (var i = 0, ii = dict_array.length; i < ii; ++i) {
        dict_array[i] = dict_array[i].toUpperCase()
    }

    this.dict_array = dict_array.sort()
}

Dict.prototype.contains_prefix = function(prefix) {
    // Binary search
    return this.search_prefix(prefix, 0, this.dict_array.length)
}

Dict.prototype.contains_exact = function(exact) {
    // Binary search
    return this.search_exact(exact, 0, this.dict_array.length)
}

Dict.prototype.search_prefix = function(prefix, start, end) {
    if (start >= end) {
        // If no more place to search, return no matter what.
        return this.dict_array[start].indexOf(prefix) > -1
    }

    var middle = Math.floor((start + end)/2)

    if (this.dict_array[middle].indexOf(prefix) > -1) {
        // If we prefix exists, return true.
        return true
    } else {
        // Recurse
        if (prefix <= this.dict_array[middle]) {
            return this.search_prefix(prefix, start, middle - 1)
        } else {
            return this.search_prefix(prefix, middle + 1, end)
        }
    }
}

Dict.prototype.search_exact = function(exact, start, end) {
    if (start >= end) {
        // If no more place to search, return no matter what.
        return this.dict_array[start] === exact
    }

    var middle = Math.floor((start + end)/2)

    if (this.dict_array[middle] === exact) {
        // If we prefix exists, return true.
        return true
    } else {
        // Recurse
        if (exact <= this.dict_array[middle]) {
            return this.search_exact(exact, start, middle - 1)
        } else {
            return this.search_exact(exact, middle + 1, end)
        }
    }
}

var board = [
    ['F', 'X', 'I', 'E']
  , ['A', 'M', 'L', 'O']
  , ['E', 'W', 'B', 'X']
  , ['A', 'S', 'T', 'U']
]

var dict = new Dict()

var b = Board.from_raw(board, dict)
b.update_potential_words()
console.log(JSON.stringify(b.words.sort(function(a, b) {
    return a.length - b.length
})))

我也用Java解决了这个问题。我的实现有269行,非常容易使用。首先,您需要创建Boggler类的一个新实例,然后用网格作为参数调用solve函数。在我的电脑上加载5万个单词的字典大约需要100毫秒,它在大约10-20毫秒内找到单词。找到的单词存储在一个数组列表中,即foundWords。

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;

public class Boggler {
    private ArrayList<String> words = new ArrayList<String>();      
    private ArrayList<String> roundWords = new ArrayList<String>(); 
    private ArrayList<Word> foundWords = new ArrayList<Word>();     
    private char[][] letterGrid = new char[4][4];                   
    private String letters;                                         

    public Boggler() throws FileNotFoundException, IOException, URISyntaxException {
        long startTime = System.currentTimeMillis();

        URL path = GUI.class.getResource("words.txt");
        BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(new File(path.toURI()).getAbsolutePath()), "iso-8859-1"));
        String line;
        while((line = br.readLine()) != null) {
            if(line.length() < 3 || line.length() > 10) {
                continue;
            }

            this.words.add(line);
        }
    }

    public ArrayList<Word> getWords() {
        return this.foundWords;
    }

    public void solve(String letters) {
        this.letters = "";
        this.foundWords = new ArrayList<Word>();

        for(int i = 0; i < letters.length(); i++) {
            if(!this.letters.contains(letters.substring(i, i + 1))) {
                this.letters += letters.substring(i, i + 1);
            }
        }

        for(int i = 0; i < 4; i++) {
            for(int j = 0; j < 4; j++) {
                this.letterGrid[i][j] = letters.charAt(i * 4 + j);
            }
        }

        System.out.println(Arrays.deepToString(this.letterGrid));               

        this.roundWords = new ArrayList<String>();      
        String pattern = "[" + this.letters + "]+";     

        for(int i = 0; i < this.words.size(); i++) {

            if(this.words.get(i).matches(pattern)) {
                this.roundWords.add(this.words.get(i));
            }
        }

        for(int i = 0; i < this.roundWords.size(); i++) {
            Word word = checkForWord(this.roundWords.get(i));

            if(word != null) {
                System.out.println(word);
                this.foundWords.add(word);
            }
        }       
    }

    private Word checkForWord(String word) {
        char initial = word.charAt(0);
        ArrayList<LetterCoord> startPoints = new ArrayList<LetterCoord>();

        int x = 0;  
        int y = 0;
        for(char[] row: this.letterGrid) {
            x = 0;

            for(char letter: row) {
                if(initial == letter) {
                    startPoints.add(new LetterCoord(x, y));
                }

                x++;
            }

            y++;
        }

        ArrayList<LetterCoord> letterCoords = null;
        for(int initialTry = 0; initialTry < startPoints.size(); initialTry++) {
            letterCoords = new ArrayList<LetterCoord>();    

            x = startPoints.get(initialTry).getX(); 
            y = startPoints.get(initialTry).getY();

            LetterCoord initialCoord = new LetterCoord(x, y);
            letterCoords.add(initialCoord);

            letterLoop: for(int letterIndex = 1; letterIndex < word.length(); letterIndex++) {
                LetterCoord lastCoord = letterCoords.get(letterCoords.size() - 1);  
                char currentChar = word.charAt(letterIndex);                        

                ArrayList<LetterCoord> letterLocations = getNeighbours(currentChar, lastCoord.getX(), lastCoord.getY());

                if(letterLocations == null) {
                    return null;    
                }       

                for(int foundIndex = 0; foundIndex < letterLocations.size(); foundIndex++) {
                    if(letterIndex != word.length() - 1 && true == false) {
                        char nextChar = word.charAt(letterIndex + 1);
                        int lastX = letterCoords.get(letterCoords.size() - 1).getX();
                        int lastY = letterCoords.get(letterCoords.size() - 1).getY();

                        ArrayList<LetterCoord> possibleIndex = getNeighbours(nextChar, lastX, lastY);
                        if(possibleIndex != null) {
                            if(!letterCoords.contains(letterLocations.get(foundIndex))) {
                                letterCoords.add(letterLocations.get(foundIndex));
                            }
                            continue letterLoop;
                        } else {
                            return null;
                        }
                    } else {
                        if(!letterCoords.contains(letterLocations.get(foundIndex))) {
                            letterCoords.add(letterLocations.get(foundIndex));

                            continue letterLoop;
                        }
                    }
                }
            }

            if(letterCoords != null) {
                if(letterCoords.size() == word.length()) {
                    Word w = new Word(word);
                    w.addList(letterCoords);
                    return w;
                } else {
                    return null;
                }
            }
        }

        if(letterCoords != null) {
            Word foundWord = new Word(word);
            foundWord.addList(letterCoords);

            return foundWord;
        }

        return null;
    }

    public ArrayList<LetterCoord> getNeighbours(char letterToSearch, int x, int y) {
        ArrayList<LetterCoord> neighbours = new ArrayList<LetterCoord>();

        for(int _y = y - 1; _y <= y + 1; _y++) {
            for(int _x = x - 1; _x <= x + 1; _x++) {
                if(_x < 0 || _y < 0 || (_x == x && _y == y) || _y > 3 || _x > 3) {
                    continue;
                }

                if(this.letterGrid[_y][_x] == letterToSearch && !neighbours.contains(new LetterCoord(_x, _y))) {
                    neighbours.add(new LetterCoord(_x, _y));
                }
            }
        }

        if(neighbours.isEmpty()) {
            return null;
        } else {
            return neighbours;
        }
    }
}

class Word {
    private String word;    
    private ArrayList<LetterCoord> letterCoords = new ArrayList<LetterCoord>();

    public Word(String word) {
        this.word = word;
    }

    public boolean addCoords(int x, int y) {
        LetterCoord lc = new LetterCoord(x, y);

        if(!this.letterCoords.contains(lc)) {
            this.letterCoords.add(lc);

            return true;
        }

        return false;
    }

    public void addList(ArrayList<LetterCoord> letterCoords) {
        this.letterCoords = letterCoords;
    } 

    @Override
    public String toString() {
        String outputString = this.word + " ";
        for(int i = 0; i < letterCoords.size(); i++) {
            outputString += "(" + letterCoords.get(i).getX() + ", " + letterCoords.get(i).getY() + ") ";
        }

        return outputString;
    }

    public String getWord() {
        return this.word;
    }

    public ArrayList<LetterCoord> getList() {
        return this.letterCoords;
    }
}

class LetterCoord extends ArrayList {
    private int x;          
    private int y;          

    public LetterCoord(int x, int y) {
        this.x = x;
        this.y = y;
    }

    public int getX() {
        return this.x;
    }

    public int getY() {
        return this.y;
    }

    @Override
    public boolean equals(Object o) {
        if(!(o instanceof LetterCoord)) {
            return false;
        }

        LetterCoord lc = (LetterCoord) o;

        if(this.x == lc.getX() &&
                this.y == lc.getY()) {
            return true;
        }

        return false;
    }

    @Override
    public int hashCode() {
        int hash = 7;
        hash = 29 * hash + this.x;
        hash = 24 * hash + this.y;
        return hash;
    }
}

首先,阅读c#语言设计师如何解决一个相关问题: http://blogs.msdn.com/ericlippert/archive/2009/02/04/a-nasality-talisman-for-the-sultana-analyst.aspx。

像他一样,您可以从字典开始,并通过从字母排序的字母数组到可以根据这些字母拼写的单词列表创建字典来规范化单词。

接下来,开始从黑板上创建可能的单词并查找它们。我怀疑这将让你走得很远,但肯定有更多的技巧可以加快速度。