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Strings

Reverse, count, compare and transform text. 51 problems · Beginner level.

51 problems

Reverse

Palindrome and anagram

Counting and frequency

Cleaning and transform

Substrings and subsequences

Longest Substring Without Repeating Charactersmedium

Pattern matching

Find a Substring (Naive Search)easy

Parsing and validation

ciphers and encoding

Caesar Ciphereasy

character sets

Pangram Checkeasy

prefix and suffix

Longest Common Prefixeasy

two pointers

character codes

ASCII Sum of a Stringeasy

mapping

Isomorphic Stringseasy

searching

Count Pattern Occurrences (Overlapping)easy

stack applications

Remove All Adjacent Duplicateseasy

words

Longest Word in a Sentenceeasy

string arithmetic

string chunks

Reverse the First k of Every 2keasy

frequency count

pattern tricks

String Rotation Checkmedium

string patterns

Zigzag Conversionmedium

parsing

sequences

Count and Saymedium

sliding window

base conversion

Spreadsheet Column Titlemedium

expand around center

Count Palindromic Substringsmedium

stack

Decode a Nested Repeat Stringmedium

greedy counter

Minimum Additions for Valid Parenthesesmedium

dynamic programming

stack and counting

Valid Parenthesis String with Wildcardsmedium

greedy intervals

Partition Labelsmedium