RECKO Hiring Off-Campus OA (2022) | Find Common Characters

Problem Statement Given a string array words, return a list of all characters that appear in every string in the array, including duplicates. The result can be returned in any order. Example Input words = ["bella","label","roller"] Output ["e","l","l"] Explanation Character 'e' appears in all three words once. Character 'l' appears in all three words at least twice. Therefore the common characters are: ["e","l","l"] Constraints 1 <= words.length <= 100 1 <= words[i].length <= 100 words[i] consists of lowercase English letters.