Code RoomPeriodic string check
MediumPrep Room Coding #1373

Periodic string check

CodingAlgorithms & data structuresMid–Senior~25 min

Given a lowercase string s, determine whether it can be constructed by taking some proper substring of it and concatenating one or more copies of that substring together. Return true if so. 'abab' is true ('ab' twice); 'aba' is false; 'aaaa' is true. Length up to a few thousand.

Implement
repeated_substring_pattern(s: str) → bool
Examples
in["abab"]outtrue
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 25 min
InputExpectedGot
["abab"]truenot run yetsample