Microsoft Online Assessment (OA) - Maximum Length of a Concatenated String with Unique Characters
Given an array of strings arr. String s is a concatenation of a sub-sequence of arr which have unique characters. Return the maximum possible length of s.
Constraints:
1 <= arr.length <= 16
1 <= arr[i].length <= 26
arr[i] contains only lower case English letters.
Example 1:
Input: ["un","iq","ue"]
Output: 4
Explanation:
All possible concatenations are "","un","iq","ue","uniq" and "ique".
Example 2:
Input: ["cha","r","act","ers"]
Output: 6
Explanation:
Possible solutions are "chaers" and "acters".
Example 3:
Input: ["abcdefghijklmnopqrstuvwxyz"]
Output: 26
Explanation:
impossible to concatenate as letters wont be unique.