我们给出两个单词数组 A 和 B。每个单词都是一串小写字母。
现在，如果 b 中的每个字母都出现在 a 中，包括重复出现的字母，那么称单词 b 是单词 a 的子集。 例如，“wrr” 是 “warrior” 的子集，但不是 “world” 的子集。
如果对 B 中的每一个单词 b，b 都是 a 的子集，那么我们称 A 中的单词 a 是通用的。
你可以按任意顺序以列表形式返回 A 中所有的通用单词。
示例 1：
输入：A = ["amazon","apple","facebook","google","leetcode"], B = ["e","o"] 输出：["facebook","google","leetcode"]
示例 2：
输入：A = ["amazon","apple","facebook","google","leetcode"], B = ["l","e"] 输出：["apple","google","leetcode"]
示例 3：
输入：A = ["amazon","apple","facebook","google","leetcode"], B = ["e","oo"] 输出：["facebook","google"]
示例 4：
输入：A = ["amazon","apple","facebook","google","leetcode"], B = ["lo","eo"] 输出：["google","leetcode"]
示例 5：
输入：A = ["amazon","apple","facebook","google","leetcode"], B = ["ec","oc","ceo"] 输出：["facebook","leetcode"]
提示：
1 <= A.length, B.length <= 100001 <= A[i].length, B[i].length <= 10A[i]和B[i]只由小写字母组成。A[i]中所有的单词都是独一无二的，也就是说不存在i != j使得A[i] == A[j]。