How should I practice Longest Palindromic Substring?

Start by reading the full statement, solve the visible examples, then compare the pattern against related ByteDance phone screen problems in FastPrep.

Is Longest Palindromic Substring associated with ByteDance?

FastPrep tags this as a ByteDance phone screen coding practice problem when the problem catalog has that company and stage context.

Problem · String

Longest Palindromic Substring

Learn this problem

● Medium

ByteDanceFULLTIMEPHONE SCREEN

Problem statement

Given a non-empty string s, return its longest contiguous palindromic substring.

A single character is a palindrome. If several longest answers exist, return the leftmost one. Your solution must use linear time.

Function

longestPalindrome(s: String) → String

Examples

Example 1

s = "babad"return = "bab"

Both bab and aba have maximum length three; bab starts first.

Example 2

s = "cbbd"return = "bb"

The longest palindromic substring is bb.

Constraints

1 <= s.length <= 200000
s contains lowercase English letters.
Your algorithm must run in O(n) time.
If several longest palindromic substrings exist, return the leftmost one.