Flip letter case
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) → strExamples
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.
0:00 of about 10 min
solution.py
InputExpectedGot
["Hello, World!"]"hELLO, wORLD!"not run yetsample