Skip the first initial interview, as I performed well in their interview one year ago. The onsite consisted of 5 rounds.

Ten questions were asked, all focused on coding. There were no design questions. One question was from "Cracking the Coding Interview."

Design an algorithm to compress a string. If there are multiple repeated characters, like 'aaaa', replace them with 'a3'. The algorithm also needs to deal with numbers and mathematical equations.