trie_complete.js

traverse(root, word) {
    if(root.isLeaf) {
      this.suggestions.push(word);
      return;
    }

    for(const letter in root.children) {
        this.traverse(root.children[letter], word + letter);
    }
}

complete(word, CHILDREN=null) {
    const root = this.find(word);

    if(!root) return this.suggestions; // cannot suggest anything

    const children = root.children;

    let spread = 0;

    for(const letter in children) {
        this.traverse(children[letter], word + letter);
        spread++; 

        if(CHILDREN && spread === CHILDREN) break;
    }

    return this.suggestions;
}

// trie.complete('pro') -> [ 'project', 'produce' ]