Strings & Pattern Matching

Build fluency with string manipulation, pattern matching, parsing, and text processing — essential for coding screens and take-home assessments.

13 exercises

mediumPython

Prompt Template Engine

Build a `PromptTemplate` class that renders template strings with variable substitution. Your class should: - Take a te...

templatesstring-processingvalidation+7

easyPython

Generate Valid Parentheses Combinations

Write a function that generates all valid combinations of `n` pairs of parentheses. A valid combination means: - Each o...

recursion

mediumPython

Reverse Polish Notation Calculator

# Reverse Polish Notation Calculator Implement a function that evaluates mathematical expressions written in Reverse Po...

stack

easyPython

Valid Bracket String Checker

Write a function that determines if a string containing brackets is valid. A valid bracket string means: - Every openin...

stack

mediumPython

String Rotation Checker

Write a function that determines if one string is a rotation of another string. A string rotation means you can take ch...

strings

hardPython

Longest Palindromic Substring

Implement a function that finds the longest palindromic substring in a given string. ## Requirements - Return the long...

strings

mediumPython

String Compression with Run-Length Encoding

# String Compression Implement a function that compresses strings using run-length encoding. This technique replaces co...

strings

mediumPython

Minimum Window Substring

# Minimum Window Substring Implement a function that finds the minimum window substring in string `s` that contains all...

sliding-window

mediumPython

Longest Substring Without Repeating Characters

# Longest Substring Without Repeating Characters Implement a function that finds the length of the longest substring wi...

sliding-window

easyPython

Reverse Words in String

Write a function that reverses the order of words in a string while preserving the spacing between them. ## Requirement...

strings

easyPython

Valid Palindrome Checker

Write a function that determines if a string is a valid palindrome, considering only alphanumeric characters and ignorin...

strings

mediumPython

Anagram Grouping

Build a function that groups an array of strings into anagram groups. Anagrams are words that contain the same letters...

algorithms

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