Digital root
Given a non-negative integer n, repeatedly replace it with the sum of its digits until a single digit (0-9) remains, then return that digit. For example 38 -> 3+8=11 -> 1+1=2. n fits in a normal integer.
Implement
digit_root(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 10 min
solution.py
InputExpectedGot
[38]2not run yetsample