Recognition signal
When should you think of Strings?
Character order, matching, parsing, or repeated substrings drive the state.
18 worked problems
Strings
Scan, compare, and build character by character. Character order, matching, parsing, or repeated substrings drive the state.
Core invariant
What must stay true?
Indices and auxiliary state describe the exact prefix or window already understood.
Practice in a deliberate order
Starter
Build the template
Core
Recognize variations
What to learn in this cluster
- 01Character scans
- 02Parsing and matching
- 03Prefix algorithms and palindromes
All Strings problems
18 of 18 walkthroughsNo matching problems. Try another title, tag, or difficulty.
- #14 Longest Common Prefixstring · scanEasy
- #58 Length of Last WordstringEasy
- #205 Isomorphic Stringsstring · hash-map · bijectionEasy
- #290 Word Patternhash map · string · bijectionEasy
- #392 Is Subsequencetwo-pointers · string · greedyEasy
- #459 Repeated Substring Patternstring · string-matchingEasy
- #5 Longest Palindromic Substringstring · two pointers · expand around centreMedium
- #6 Zigzag Conversionstring · simulationMedium
- #8 String to Integer (atoi)string · parsingMedium
- #12 Integer to Romanstring · math · greedyMedium
- #28 KMP Algorithm / LPS Arraystring · kmp · pattern-matchingMedium
- #38 Count and Saystring · simulationMedium
- #165 Compare Version Numbersstring · two-pointersMedium
- #187 Repeated DNA Sequenceshash-table · string · sliding-windowMedium
- #647 Palindromic Substringsstring · two pointers · expand around centreMedium
- GFG Rabin-Karp Algorithmstring · rolling-hash · pattern-matchingMedium
- GFG Z Functionstring · z-algorithm · pattern-matchingMedium
- #68 Text Justificationstrings · simulationHard
Continue the cluster