使用trie自动完成

Question

我正在研究一个自动完成脚本,正在考虑使用trie.我的问题是我希望返回匹配的所有内容.因此,例如我输入字母,r我希望r返回所有条目.然后所有条目都以re等等开头.这对于trie是可行的,它将如何工作.此外,如果有更好的方式,我愿意接受建议.我问的原因是它似乎很复杂,并且需要进行大量处理才能将所有节点都归结为r分支.

是的,我可能正在重新发明轮子,但我想了解它是如何工作的.

Answer 1

你绝对可以使用trie来做到这一点.以下是我汇集的一些代码,可以指出正确的方向:

var tokenTree = function (tokenArray) {
  var createLetterObject = function (l) {
    var pChildren = [];

    var getMatchingWords = function (characterArr, availableWords, children) {
        if (characterArr.length === 0) {
            for (var child in children) {
                if ({}.hasOwnProperty.call(children, child)) {
                    var currentChild = children[child];

                    var words = currentChild.getWords(characterArr);

                    for (var pos in words) {
                        if ({}.hasOwnProperty.call(words, pos)) {
                            availableWords.push(words[pos]);
                        }
                    }

                    if (currentChild.word) {
                        availableWords.push(currentChild.word);
                    }
                }
            }
        } else {
            var currentCharacter = characterArr.pop();
            getMatchingWords(characterArr, availableWords, children[currentCharacter].children);
        }
    };

    function doGetWords(wordPart) {
        var len = wordPart.length;
        var ar = [];
        var wordList = [];

        for (var ii = len - 1; ii >= 0; ii --) {
            ar.push(wordPart[ii].toUpperCase());
        }

        getMatchingWords(ar, wordList, pChildren);

        return wordList;
    }

    return {
        letter: l,
        children: pChildren,
        parent: null,
        word: null,
        getWords: doGetWords
    };
};

var startingPoint = createLetterObject();

function parseWord(wordCharacterArray, parent, fullWord) {
    if (wordCharacterArray.length === 0) {
        parent.word = fullWord;
        return;
    }

    var currentCharacter = wordCharacterArray.pop().toUpperCase();

    if (!parent.children[currentCharacter]) {
        parent.children[currentCharacter] = createLetterObject(currentCharacter);
    }

    parseWord(wordCharacterArray, parent.children[currentCharacter], fullWord);
}

for (var counter in tokenArray) {
    if ({}.hasOwnProperty.call(tokenArray, counter)) {
        var word = tokenArray[counter];

        if (!word) {
            continue;
        }

        var ar = [];

        var wordLength = word.length;

        for (var ii = wordLength - 1; ii >= 0; ii--) {
            ar.push(word[ii]);
        }

        parseWord(ar, startingPoint, word);
    }
}

  return startingPoint;
};

用法

var tokens = ["Token", "words", "whohaa", "mommy", "test", "wicked"];
var tree = tokenTree(tokens);
var currentTokenSet = 'w'; 
var list = tree.getWords(currentTokenSet);

// it will return words,whohaa,wicked.
console.log(list) 

我并不是说这是最好或最有效的方式,但它至少应该让你指向正确的方向.

这是一个显示它工作的jsfiddle:https://jsfiddle.net/es6xp8h9/