Compress and Decompress String (Excel-like Encoding)

Given a string s consisting of uppercase letters A-Z, implement two functions compress(s) and decompress(t) such that: decompress(compress(s)) == s The encoding uses an Excel-like count representation: for each run of identical consecutive characters, encode it as char + count, where count is written in Excel column style (A=1, B=2, ..., Z=26, AA=27, etc.). Examples: AAAA has count 4, which is D in Excel style, so it becomes AD. ZZ has count 2, which is B, so it becomes ZB. Requirements Implement: compress(s: str) -> str decompress(t: str) -> str Constraints 1 <= len(s) <= 2e5 s contains only A-Z t is guaranteed to be valid output of compress Target O(n) time and reasonable extra space Example Input: s = "AAAABCC" -> output compress(s) (according to the rule) Input: t = "AD" -> output decompress(t) = "AAAA" (If you assume a different but self-consistent definition of "Excel-like" counting, state it clearly.) Example Input AAAA Output AD