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C++ coding challenges
226 challenges you can solve in C++, from first loops to graphs, dynamic programming and machine learning. Write your code in the browser, run the tests instantly and get an AI review.
Easy · 134 Medium · 68 Hard · 24
Skills you'll practise: CountingDigit extractionString splitting2D listsArithmeticFormulasListsLoopsConditionsDivisibilityFloating pointGradient descent
- Python · C++ · C#
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- 226
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All challenges
Search by topic, language, or difficulty.
Easy
Epsilon-Greedy Multi-Armed Bandit
Balance exploration and exploitation on a multi-armed bandit with epsilon-greedy action selection.
You'll learn
Explore vs exploitBandits
No solutions yet
Easy
DNA to RNA Transcription
Build an RNA string by replacing every DNA character with its partner.
You'll learn
Character mappingTranslation tables
No solutions yet
Easy
Title Case
Capitalize the first letter of every word.
You'll learn
String methodsCapitalization
No solutions yet
Easy
Every Other Character
Keep the characters at even positions.
You'll learn
String indexingSteps
No solutions yet
Easy
Countdown to Liftoff
Count down from a number and end with Liftoff!
You'll learn
Reverse loopsLists
No solutions yet
Easy
Activation Functions
Apply sigmoid, ReLU, Leaky ReLU or tanh to every value in a list.
You'll learn
SigmoidReLU and tanh
No solutions yet
Easy
Anagram Check
Check whether two phrases use the same letters.
You'll learn
SortingFrequency counts
No solutions yet
Medium
Two Nonattacking Knights
Count safe placements of two knights for each square board size.
You'll learn
Counting placementsAttack patterns
No solutions yet
Easy
Markov Chain State Distribution
Propagate a probability distribution through a Markov chain's transition matrix for a number of steps.
You'll learn
Markov chainsProbability
No solutions yet
Easy
Body Mass Index
Compute BMI from weight and height.
You'll learn
FormulasFloating point
No solutions yet
Easy
Reverse a String
Return the characters of a string in reverse order.
You'll learn
Reverse iterationSlicing
No solutions yet
Medium
Longest Common Subsequence Length
A subsequence is formed by deleting zero or more elements while preserving the order of the remaining elements.
You'll learn
2D DP tablesMemory optimization
No solutions yet
Easy
Loss Functions: MSE, MAE and Cross-Entropy
Measure how wrong a model's predictions are with mean squared error, mean absolute error or binary cross-entropy.
You'll learn
MSECross-entropy
No solutions yet
Easy
Cart Total With Discount
Total a shopping cart and apply a discount above a threshold.
You'll learn
ListsDiscount rules
No solutions yet
Hard
Hotel Room Allocation
Assign arriving groups in order.
You'll learn
Range maximum queriesPoint updates
No solutions yet
Medium
Forward Propagation in a Two-Layer Network
Run inputs through a hidden ReLU layer and a sigmoid output layer.
You'll learn
Forward passMulti-layer networks
No solutions yet
Medium
Gradients of a Single Neuron
Use the chain rule to find how the loss changes with each weight and the bias of a sigmoid neuron.
You'll learn
Chain ruleGradients
No solutions yet
Easy
Swap First and Last
Exchange the first and last items of a list.
You'll learn
List indexingSwapping
No solutions yet
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