Untitled

const EOS = '</EOS>';

var WordDictionary = function() {
    this.words = new Set();
    this.trie = new Map();
    this.wordsToIndex = []; // this trick beats 99.73%
};

/** 
 * @param {string} word
 * @return {void}
 */
WordDictionary.prototype.addWord = function(word) {
    if (!this.words.has(word)) {
        this.words.add(word);
        this.wordsToIndex.push(word);
    }    
};

/** 
 * @param {string} word
 * @return {void}
 */
WordDictionary.prototype.indexWord = function(word) {
    let triePointer = this.trie;
    for (const letter of word) {
        if(!triePointer.has(letter)) {
            triePointer.set(letter, new Map());
        }
        triePointer = triePointer.get(letter);
    }
    triePointer.set(EOS, null);
}

/** 
 * @param {string} word
 * @return {boolean}
 */
WordDictionary.prototype.search = function(word) {
    if (word.includes('.')) {
        if (this.wordsToIndex.length > 0) {
            this.wordsToIndex.forEach(w => {
                this.indexWord(w);
            });
            this.wordsToIndex = [];
        }
        return trieSearch(this.trie, word, 0);
    }

    return this.words.has(word);
};

function trieSearch(root, word, index) {
    if (root === null) {
        return false;
    }

    if (word[index] === undefined) {
        return root.has(EOS);
    }

    if (word[index] === '.') {
        for (let [, nextRoot] of root.entries()) {
            if (trieSearch(nextRoot, word, index+1)) {
                return true;
            }
        }
        return false;
    }
    
    if(!root.has(word[index])) {
        return false;
    }

    return trieSearch(root.get(word[index]), word, index+1);
}

/** 
 * Your WordDictionary object will be instantiated and called as such:
 * var obj = new WordDictionary()
 * obj.addWord(word)
 * var param_2 = obj.search(word)
 */