Numbers with distinct digits
Given an integer `k`, count how many non-negative integers x with 0 <= x < 10^k have all distinct digits. For k = 0 the range is just {0}, so the answer is 1. 0 <= k <= 9.
Implement
count_numbers_with_unique_digits(k: int) → intExamples
in
[2]out91What 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 20 min
solution.py
InputExpectedGot
[2]91not run yetsample