Code RoomLongest palindromic subsequence
HardPrep Room Coding #1581

Longest palindromic subsequence

CodingAlgorithms & data structuresSenior–Staff~35 min

Given a string, return the length of its longest palindromic subsequence (characters need not be contiguous).

Implement
longest_palindrome_subseq(s: str) → int
Examples
in["bbbab"]out4
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 35 min
InputExpectedGot
["bbbab"]4not run yetsample