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.
📐 工作原理与说明
字母重排组合数 = 字母数 n 的阶乘 ÷(各重复字母出现次数阶乘之积);从字母集合中枚举长度不低于 3 的子集并做全排列,与词典比对去重得到所有可拼单词;按长度降序或字典序输出,得分常按单词长度或稀有度计算。