Google Online Assessment 2021 (OA) - Longest Palindrome
A string is a palindrome if it reads the same backward as forwards. For example, "madam" and "racecar" are palindromes, but "milk" is not.
We are given an array of N strings in which each string consist of two lowercase English letters. We would like to join as many strings together as possible in order to obtain a palindrome.
Input
arr: an array of length N containing two-letter strings
Output
the length of longest palindrome that can be created by joining as many strings together as possible form arr
Examples
Example 1:
Input:
arr = ['ck', 'kc', 'ho', 'kc']
Output: 4
Explanation:
The longest palindrome are "ckkc" and "kcck", and their lengths are both equal to 4.