Programming Challenges

Strengthen your problem-solving skills with language-neutral challenges you can solve in Python, C++, or C#. Every submission is checked by automated tests and reviewed by AI.

  • Python · C++ · C#
  • Automated tests
  • AI code review
  • Community solutions
Learning path
150
Challenges
2
Solutions shared
3
Languages

All challenges

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25 challenges
Hard

Find Many Patterns in Text

For each requested pattern, decide whether it appears as a contiguous substring anywhere in the shared text.

Pattern-matchingStringsTries
No solutions yet
Easy

Pangram Check

A pangram contains every English letter at least once.

SetsStrings
No solutions yet
Easy

Roman Numeral Value

Convert a Roman numeral to a number.

BeginnerLookup-tablesStringsStudent-beginner
No solutions yet
Easy

Every Other Character

Keep the characters at even positions.

BeginnerLearning-pathStrings
No solutions yet
Easy

DNA to RNA Transcription

Build an RNA string by replacing every DNA character with its partner.

MappingStrings
No solutions yet
Hard

Word Break

Decide whether text can be split into dictionary words.

AdvancedDynamic-programmingHackathonStrings
No solutions yet
Easy

Word Tile Score

Add the tile values for every letter in a word.

Lookup-tablesStrings
No solutions yet
Medium

Recursive Palindrome

Check a palindrome recursively, ignoring case and punctuation.

BeginnerLearning-pathRecursionStrings
No solutions yet
Easy

Count Uppercase Letters

Count the capital letters in a text.

BeginnerLearning-pathStrings
No solutions yet
Easy

Initials From a Name

Build uppercase initials from a full name.

BeginnerLearning-pathStrings
No solutions yet
Hard

Minimum Window Substring

Find the shortest piece of text containing all required characters.

AdvancedCompetitive-programmingSliding-windowStrings
No solutions yet
Easy

Replace Spaces With Dashes

Turn spaces into dashes to make a URL-style slug.

BeginnerLearning-pathStrings
No solutions yet
Easy

First Unique Character

Find the first character that appears only once.

BeginnerDictionariesStringsStudent-beginner
No solutions yet
Easy

Character Frequency

Count how often each character appears.

BeginnerDictionariesStringsStudent-beginner
No solutions yet
Easy

Longest Word

Find the longest word in a sentence.

BeginnerStringsStudent-beginner
No solutions yet
Easy

Password Rules Check

Check a password against simple strength rules.

BeginnerConditionsLearning-pathStrings
No solutions yet
Easy

Palindrome String

Check whether text reads the same forwards and backwards.

BeginnerStringsStudent-beginner
No solutions yet
Easy

Count Words

Count the words in a sentence.

BeginnerStringsStudent-beginner
No solutions yet