CodingEasycod-g1371

Subject StringsLevel Entry–Mid~10 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

Given a string, return a copy where the case of every ASCII letter is flipped: lowercase becomes uppercase and uppercase becomes lowercase. All other characters stay unchanged. Implement the transformation yourself using character-code ranges rather than a library swap-case helper. For example, 'Hello, World!' becomes 'hELLO, wORLD!'.

Implement

flip_case(s: str) → str

Examples

in["Hello, World!"]out"hELLO, wORLD!"

What a strong answer looks like

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.

Learn the concepts

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.

Run or narrate your approach, then ask the coach.