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# [1002. Find Common Characters](https://leetcode.com/problems/find-common-characters/)
## 题目
Given an array `A` of strings made only from lowercase letters, return a list of all characters that show up in all strings within the list **(including duplicates)**. For example, if a character occurs 3 times in all strings but not 4 times, you need to include that character three times in the final answer.
You may return the answer in any order.
**Example 1:**
Input: ["bella","label","roller"]
Output: ["e","l","l"]
**Example 2:**
Input: ["cool","lock","cook"]
Output: ["c","o"]
**Note:**
1. `1 <= A.length <= 100`
2. `1 <= A[i].length <= 100`
3. `A[i][j]` is a lowercase letter
## 题目大意
给定仅有小写字母组成的字符串数组 A返回列表中的每个字符串中都显示的全部字符包括重复字符组成的列表。例如如果一个字符在每个字符串中出现 3 次,但不是 4 次,则需要在最终答案中包含该字符 3 次。你可以按任意顺序返回答案。
## 解题思路
- 简单题。给出一个字符串数组 A要求找出这个数组中每个字符串都包含字符如果字符出现多次在最终结果中也需要出现多次。这一题可以用 map 来统计每个字符串的频次,但是如果用数组统计会更快。题目中说了只有小写字母,那么用 2 个 26 位长度的数组就可以统计出来了。遍历字符串数组的过程中,不过的缩小每个字符在每个字符串中出现的频次(因为需要找所有字符串公共的字符,公共的频次肯定就是最小的频次),得到了最终公共字符的频次数组以后,按顺序输出就可以了。