Minimum Remove to Make Valid Parentheses — Stack Solution
Solve LeetCode 1249 Minimum Remove to Make Valid Parentheses using a stack. Two-pass and one-pass approaches with Python code and traces.
·5 min read · #dsa#stacks#strings
#strings
28 posts · page 1 of 1
Simplify Unix Path Using a Stack — LeetCode 71 Solution
Solve Simplify Path LeetCode 71 with a stack. Handle ., .., multiple slashes, and edge cases. Python solution with step-by-step trace.
·4 min read · #dsa#stacks#strings
Tag Validator — Stack-Based XML Parsing (LeetCode 591)
Tag Validator solved with stack-based HTML/XML tag matching and CDATA parsing. Python solution with edge cases, step-by-step trace, and complexity analysis.
·6 min read · #dsa#stacks#strings
Anagram Problems: Patterns and Solutions
Master anagram problems — valid anagram checks, grouping anagrams by sorted and frequency keys, finding all anagrams in a string with sliding windows, and the minimum window substring problem.
·11 min read · #dsa#strings#intermediate
String Encoding and Decoding Patterns
Master string encoding and decoding — delimiter-based encode/decode, run-length encoding, decoding nested bracket strings with stacks, string compression, and serialization patterns.
·12 min read · #dsa#strings#intermediate
String Hashing Techniques for Pattern Matching
Master string hashing for pattern matching — polynomial hashing, rolling hash for Rabin-Karp, double hashing, repeated DNA sequences, and longest duplicate substring.
·15 min read · #dsa#strings#advanced
String Interview Patterns: Complete Guide
A complete guide to string interview patterns — top 20 patterns, two-pointer on strings, frequency map technique, sliding window template, when to use Trie vs HashMap, common mistakes, and a complexity cheatsheet.
·15 min read · #dsa#strings#interviews
Sliding Window on Strings: Patterns and Templates
Sliding window on strings with reusable templates — longest substring without repeating, minimum window substring, K distinct characters, and permutation check.
·11 min read · #dsa#strings#intermediate
String Manipulation Tricks for Interviews
Essential string manipulation tricks — reverse words, reverse vowels, string rotation check, repeated substring pattern, multiply strings, and add binary.
·11 min read · #dsa#strings#intermediate
String Palindrome Patterns: Complete Guide
Master palindrome problems — longest palindromic substring with expand-around-center and Manacher's algorithm, counting palindromic substrings, and palindrome partitioning.
·11 min read · #dsa#strings#intermediate
Parentheses Problems: From Valid to Generate
Master parentheses problems — validate with stacks, generate all combinations with backtracking, find the longest valid substring with DP and stack, remove invalid parentheses with BFS, and more.
·13 min read · #dsa#strings#intermediate
String Subsequence Problems
Master string subsequence problems — check subsequences with two pointers, count distinct subsequences with DP, find the longest common subsequence, and build the shortest common supersequence.
·13 min read · #dsa#strings#intermediate
Trie Applications: Autocomplete, Word Break, and More
Advanced Trie applications — autocomplete system, search suggestions, word break with Trie, longest word in dictionary, replace words, and magic dictionary.
·14 min read · #dsa#strings#intermediate
Rabin-Karp String Matching with Rolling Hash
Learn the Rabin-Karp algorithm for string matching using rolling hash. Covers polynomial hashing, collision avoidance, multiple pattern matching, and comparison with KMP.
·11 min read · #dsa#strings#intermediate
Suffix Arrays: Construction, LCP, and Applications
Learn suffix arrays from scratch -- naive and O(n log^2 n) construction, LCP arrays, pattern searching with binary search, and applications like longest repeated substring.
·12 min read · #dsa#strings#advanced
Z-Algorithm for Linear-Time String Matching
Master the Z-algorithm for pattern matching in O(n) time. Learn Z-array construction, the Z-box optimization, and applications like finding string periods and distinct substrings.
·10 min read · #dsa#strings#intermediate
Advanced String Algorithms: Z, Rabin-Karp & Suffix Arrays
Master advanced string algorithms — Z-algorithm, Rabin-Karp rolling hash, suffix arrays, Aho-Corasick multi-pattern matching, Manacher's palindrome algorithm, and string hashing techniques.
·11 min read · #dsa#strings#advanced
KMP String Matching Algorithm Explained
Master the Knuth-Morris-Pratt algorithm — build the failure function, avoid redundant comparisons, and solve pattern matching problems in O(n + m) time.
·5 min read · #dsa#strings#intermediate
C++ std::string_view Explained
Learn how std::string_view gives you cheap, non-owning views into strings — when to use it, how it speeds up code, and how to avoid dangling references.
·4 min read · #cpp#strings#performance
Pandas String Methods Tutorial
A practical tour of the Pandas .str accessor: cleaning text, extracting patterns, splitting and joining, dealing with missing values, and writing string code that stays fast.
·4 min read · #pandas#python#strings
Python f-Strings Formatting Guide
A complete guide to Python f-strings — basic interpolation, format specifiers for numbers and dates, alignment and padding, debug syntax, and when to choose other formatting methods.
·5 min read · #python#strings#formatting
Edit Distance: 2D DP Step by Step
Edit Distance fully unpacked — the three-operation recurrence, the 2D table, and the rolling-array space optimization that makes interviewers nod.
·6 min read · #dsa#leetcode#dp
Longest Palindromic Substring — Expand Around Center
Walk through the Longest Palindromic Substring problem using the expand-around-center technique. Compare brute force, DP, and the optimal approach with examples.
·7 min read · #dsa#leetcode#strings
Strings in DSA: Operations and Patterns
An introduction to strings for data structures and algorithms — immutability, indexing, slicing, common operations, ASCII versus Unicode, and the two-pointer and frequency-counter patterns you will use everywhere.
·8 min read · #dsa#strings#beginners
String Pattern Matching: Naive, KMP, and Rabin-Karp
A practical tour of substring search — the naive O(n·m) scan, the KMP algorithm with its LPS array, and the Rabin-Karp rolling hash. Worked examples, code, and intuition for when to use each.
·8 min read · #dsa#strings#intermediate
Strings: 8 Practice Problems with Solutions
Eight classic string problems with worked Python solutions — Valid Anagram, Group Anagrams, Longest Substring Without Repeating Characters, Longest Palindromic Substring, and more.
·9 min read · #dsa#strings#practice
Strings and Template Literals in JavaScript
A practical guide to JavaScript strings — template literals, indexing, the essential methods, immutability, and the modern ways to slice, search, and transform text.
·7 min read · #javascript#beginners#strings
Strings in Python: Everything a Beginner Needs
A thorough introduction to Python strings — creation, escape sequences, indexing, slicing, the essential methods, f-strings, and why strings are immutable.
·7 min read · #python#beginners#strings