Strings

Master string manipulation and pattern matching

Strings are sequences of characters and one of the most commonly used data types in programming. Understanding string manipulation, searching, and pattern matching is essential for solving a wide variety of real-world problems.

Key Concepts

Immutable in many languages (Java, Python)
Common operations: concatenation, substring, search
Two pointers technique for palindromes and anagrams
Pattern matching with KMP, Rabin-Karp algorithms
String building with StringBuilder for efficiency

Problems

Valid PalindromeEasy

Check if a string is a palindrome ignoring non-alphanumeric characters

Two PointersString Manipulation

Valid Anagram

EasySoon

Determine if two strings are anagrams of each other

Hash MapSorting

Longest Substring Without Repeating

MediumSoon

Find length of longest substring without repeating characters

Sliding WindowHash Map

Longest Palindromic Substring

MediumSoon

Find the longest palindromic substring in a string

Dynamic ProgrammingExpand Around Center

Group Anagrams

MediumSoon

Group strings that are anagrams of each other

Hash MapSorting

Minimum Window Substring

HardSoon

Find minimum window containing all characters of another string

Sliding WindowHash Map

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