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:

1arr = ['ck', 'kc', 'ho', 'kc']

Output: 4

Explanation:

The longest palindrome are "ckkc" and "kcck", and their lengths are both equal to 4.

Try it yourself

Solution

Title

Script

Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.

Contrary to popular belief, Lorem Ipsum is not simply random text.

1  >>> a = [1, 2, 3]
2  >>> a[-1]
3  3

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