Asked these 2 questions.\n\n1. https://leetcode.com/problems/valid-palindrome/\n    Follow up 1: if a specific charset needs to be matched (a,e,z) and exclude anything else. How would you do it? (Use a hashset for charset to be matched).\n    Follow up 2: if a string is infinitely large and you cannot load it all in RAM and can only access blocks of string which will contain some k contiguous chars. (Access 1st and last block and keep checking)\n\t\n2. https://leetcode.com/problems/subarray-sum-equals-k/\n\nHow to answer the 2 follow-up questions for Q-1?

Asked these 2 questions.\n\n1. https://leetcode.com/problems/valid-palindrome/\n    Follow up 1: if a specific charset needs to be matched (a,e,z) and exclude a