A Google recruiter reached out to my email, asking if I was interested in interning at Google for the summer of 2022. I said yes, and we scheduled a call. After a few weeks, she sent me an invitation link to apply. I did apply and was scheduled for a technical interview in some weeks' time. Two coding challenges, 90 minutes, back to back.

Given a non-empty string consisting of n letters, return the number of possible splits into two parts such that the number of distinct letters in each part is equal.