String Topics

Master essential string problems and patterns frequently asked in interviews.

•   01 Longest Palindromic Substring Find the longest substring that is a palindrome
•   02 Longest Substring Without Repeating Characters Sliding window pattern to track unique characters
•   03 Valid Anagram Hash map pattern to check frequency of characters
•   04 Group Anagrams Sorting & hash-based grouping of strings
•   05 String Matching / Pattern Matching KMP / Rabin-Karp algorithm for substring search

WONDERING, HOW DOES IT COVER PATTERNS?
These problems cover the most important string patterns for interviews:

Longest Palindromic Substring → Expand around center, dynamic programming, palindrome checking.
Longest Substring Without Repeating Characters → Sliding window, hash map to track characters.
Valid Anagram → Hashing frequency counts, comparison.
Group Anagrams → Sort string or use character count as key in hash map.
String Matching / Pattern Matching → KMP algorithm, rolling hash (Rabin-Karp) for efficient substring search.

Together, they ensure you understand palindromes, sliding window, hash-based frequency, grouping, and efficient substring search techniques in strings.