Maximum Length of a Concatenated String with Unique Characters
You are given an array of strings arr. A string s is formed by the concatenation of a subsequence of arr that has unique characters.
Return the maximum possible length of s.
A subsequence is an array that can be derived from another array by deleting some or no elements without changing the order of the remaining elements.
Example 1
Input
arr = ["un","iq","ue"]Output
4All valid concatenations include "", "un", "iq", "ue", "uniq", and "ique", so the maximum length is 4.
Example 2
Input
arr = ["cha","r","act","ers"]Output
6Possible longest valid concatenations are "chaers" and "acters", each with length 6.
Constraints
- 1 <= arr.length <= 16
- 1 <= arr[i].length <= 26
- arr[i] contains only lowercase English letters.