Given a set of letters, find every English word of three letters or more that can be formed, sorted by length or alphabetically — for word games and brain training.
📐 工作原理與說明
字母重排組合數 = 字母數 n 的階乘 ÷(各重複字母出現次數階乘之積);從字母集合中列舉長度不低於 3 的子集並做全排列,與詞典比對去重得到所有可拼單詞;按長度降序或字典序輸出,得分常按單詞長度或稀有度計算。