Smallest repunit base
Given an integer n (3 <= n <= 10^18) provided as a Python int, find the smallest base k >= 2 such that the representation of n in base k consists entirely of 1s, i.e. n = 1 + k + k^2 + ... + k^m for some m >= 1. Return k. For example n = 13 = 111 in base 3, so the answer is 3. Every n has the trivial representation 11 in base n-1, so an answer always exists.
Implement
smallest_good_base(n: int) → intExamples
in
[13]out3What 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 35 min
solution.py
InputExpectedGot
[13]3not run yetsample