Longest common substring
Return the length of the longest substring that appears contiguously in BOTH strings a and b (the longest common substring, not subsequence). For example "abcdxyz" and "xyzabcd" share "abcd" of length 4. Either string may be empty (answer 0). Strings can be up to ~1000 characters; an O(len(a)*len(b)) DP is acceptable, though suffix automata/arrays give better asymptotics.
Implement
longest_common_substring_len(a: str, b: str) → intExamples
in
["AcornforAcorn","AcornQuiz"]out5What 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 30 min
solution.py
InputExpectedGot
["AcornforAcorn","AcornQuiz"]5not run yetsample