Description
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.
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。
题目链接：https://leetcode.com/problems/find-common-characters/
Difficulty: easy
Example 1:
Input: ["bella","label","roller"]
Output: ["e","l","l"]
Example 2:
Input: ["cool","lock","cook"]
Output: ["c","o"]
Note:
- 1 <= A.length <= 100
- 1 <= A[i].length <= 100
- A[i][j] is a lowercase letter
分析
- 遍历A的第一项的每个字母ind，逐次做一下操作；
- 遍历A其他的项，若包含ind，则将该项中的ind去掉；
- 若A所有的项都包含ind，则将ind加入到ans中；
- 返回ans。
参考代码
class Solution(object):
def commonChars(self, A):
ans=[]
if(len(A)==1):
return list(A[0])
index = A[0]
for ind in index:
for i in range(1,len(A)):
if(ind in A[i]):
position=A[i].index(ind)
A[i]=A[i][:position]+A[i][position+1:]
else:
break
else:
ans.append(ind)
return ans