Code RoomCount palindromic substrings
MediumPrep Room Coding #704

Count palindromic substrings

CodingAlgorithms & data structuresMid–Senior~20 min

Return the number of palindromic substrings of s, counting substrings at different positions separately even if they are equal as strings. Single characters count, so "aaa" has 6 palindromic substrings: a, a, a, aa, aa, aaa. The string can be a few thousand characters; an O(n^2) expand-around-center solution is expected.

Implement
count_palindromic_substrings(s: str) → int
Examples
in["aaa"]out6
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 20 min
InputExpectedGot
["aaa"]6not run yetsample