Digital root
Repeatedly sum a non-negative integer's digits until a single digit remains; return it (the digital root).
Implement
add_digits(n: int) → intExamples
in
[38]out2What 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 15 min
solution.py
InputExpectedGot
[38]2not run yetsample