Question
Given a string representing arbitrarily nested ternary expressions, evaluate it and return the result as a string. The expression uses single-digit numbers `0-9` and the letters `T` (true) and `F` (false) as conditions, with the form `condition?if_true:if_false`. Grouping is right-to-left associative and the input is guaranteed valid. Return the final single-character result.
parse_ternary(expr: str) → str["T?2:3"]out"2"State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.