[Solved] Given a string array words, return an array of all characters that show up in all strings within the words (including duplicates). You may return the answer in any order.

Question

Given a string array words, return an array of all characters that show up in all strings within the words (including duplicates). You may return the answer in any order.

Example 1:

Input: words = ["bella","label","roller"]
Output: ["e","l","l"]

Example 2:

Input: words = ["cool","lock","cook"]
Output: ["c","o"]

Constraints:

• 1 <= words.length <= 100
• 1 <= words[i].length <= 100
• words[i] consists of lowercase English letters.

Python Solution

from collections import Counter
class Solution:
    def commonChars(self, A: List[str]) -> List[str]:
        d=Counter(A[0])
        
        for a in A:
            d=d&Counter(a)
        
        return list(d.elements())