prefix-xor Interview Questions

In this Deloitte coding question, you are tasked with identifying the longest contiguous substring within a given string where every distinct character present in that substring appears an even number of times. The input string consists solely of lowercase English letters. This problem challenges your ability to efficiently process strings, track character frequencies, and apply techniques like prefix sums or bitmasks to optimize the search for the desired substring. The full problem and model solution require a subscription.