Distinct subsequence count
Given strings s and t, count the number of distinct subsequences of s that equal t. A subsequence keeps relative order but may drop characters. The count fits in a 64-bit integer. Either string may be empty; the empty string is a subsequence of any string exactly once.
Implement
distinct_subseq(s: str, t: str) → intExamples
in
["rabbbit","rabbit"]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 25 min
solution.py
InputExpectedGot
["rabbbit","rabbit"]3not run yetsample