K-th smallest distinct substring
Given a lowercase string s, return the lexicographically smallest DISTINCT substring that is the k-th smallest among all distinct non-empty substrings (1-indexed k). If k exceeds the number of distinct substrings, return the empty string. For s='aab', the sorted distinct substrings are 'a','aa','aab','ab','b'; k=3 gives 'aab'. Length up to a few hundred.
Implement
kth_distinct_substring(s: str, k: int) → strExamples
in
["aab",3]out"aab"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 38 min
solution.py
InputExpectedGot
["aab",3]"aab"not run yetsample