Member of Technical Staff

You are given a string 'str' of length 'N'.

Your task is to return the longest palindromic substring. If there are multiple strings, return any.

A substring is a contiguous segment of a string.

For example :

str = "ababc"

The longest palindromic substring of "ababc" is "aba", since "aba" is a palindrome and it is the longest substring of length 3 which is a palindrome. 

There is another palindromic substring of length 3 is "bab". Since starting index of "aba" is less than "bab", so "aba" is the answer.

I was asked to design ludo snake ladder game.

There are three ticket window on railway station, at two window tickets are being given at same speed and at third window it takes twice the time taken at other window. whenever a person is coming a guard redirects him to a specific window to ensure average waiting time is minimum. How guard is doing this ?