Challenge Library
Coding Challenges
5,893 curated questions across every arena — browse by topic, then jump into a live 2-minute battle to put them to the test.
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5,893 challenges total
- Multiple ChoiceIntermediate
doctest Module
pythonintermediate - Multiple ChoiceIntermediate
cProfile Module
pythonintermediate - Multiple ChoiceIntermediate
coverage.py
pythonintermediate - Multiple ChoiceIntermediate
pytest.raises
pythonintermediate - Multiple ChoiceIntermediate
Mock Return Value
pythonintermediate - Multiple ChoiceBeginner
Test Discovery
pythonbeginner - Multiple ChoiceBeginner
Test Coverage Report
pythonbeginner - Code AnalysisIntermediate
pytest parametrize (Analysis)
pythonintermediate - Code AnalysisBeginner
mock return_value
pythonbeginner - Code AnalysisBeginner
assertEqual output
pythonbeginner - Code AnalysisIntermediate
assertRaises context
pythonintermediate - Code AnalysisIntermediate
patch decorator
pythonintermediate - Code AnalysisIntermediate
doctest example
pythonintermediate - Code AnalysisIntermediate
MagicMock attributes
pythonintermediate - Code AnalysisHard
Class Variable Shadow
code-analysisPythonlanguage - Code AnalysisHard
Decorator Order
code-analysisPythonlanguage - Code AnalysisBeginner
Dict Merge 3.9+
code-analysisPythonlanguage - Code AnalysisBeginner
F-string Format Spec
code-analysisPythonlanguage - Code AnalysisIntermediate
Generator Exhaustion
code-analysisPythonlanguage - Code AnalysisHard
is vs == (int cache)
code-analysisPythonlanguage - Code AnalysisIntermediate
Lambda Late Binding
code-analysisPythonlanguage - Code AnalysisIntermediate
List Comp Scope
code-analysisPythonlanguage - Code AnalysisHard
Multiple Inheritance MRO
code-analysisPythonlanguage - Code AnalysisHard
Mutable Default Arg
code-analysisPythonlanguage - Code AnalysisIntermediate
nonlocal Keyword
code-analysisPythonlanguage - Code AnalysisBeginner
Reversed String
code-analysisPythonlanguage - Code AnalysisBeginner
Set Comprehension
code-analysisPythonlanguage - Code AnalysisBeginner
Star Unpacking
code-analysisPythonlanguage - Code AnalysisHard
String Interning
code-analysisPythonlanguage - Code AnalysisBeginner
Truthiness Edge Cases
code-analysisPythonlanguage - Code AnalysisIntermediate
Try Else Finally Order
code-analysisPythonlanguage - Code AnalysisIntermediate
Tuple Mutable Item
code-analysisPythonlanguage - Code AnalysisHard
Walrus in Comprehension
code-analysisPythonlanguage - Code AnalysisBeginner
Unequal Zip
code-analysisPythonlanguage - Multiple ChoiceIntermediate
[Algorithms] Data structure Level-order graph traversal
qaalgosalgosqa - Multiple ChoiceIntermediate
[Algorithms] Shortest path Level-order graph traversal
qaalgosalgosqa - Multiple ChoiceIntermediate
[Algorithms] Visited Level-order graph traversal
qaalgosalgosqa - Multiple ChoiceIntermediate
[Algorithms] Complexity Level-order graph traversal
qaalgosalgosqa - Multiple ChoiceIntermediate
[Algorithms] Bidirectional Level-order graph traversal
qaalgosalgosqa - Multiple ChoiceBeginner
[Algorithms] Precondition O(log n) on sorted array
qaalgosalgosqa - Multiple ChoiceBeginner
[Algorithms] Mid calc O(log n) on sorted array
qaalgosalgosqa - Multiple ChoiceBeginner
[Algorithms] Termination O(log n) on sorted array
qaalgosalgosqa - Multiple ChoiceBeginner
[Algorithms] First occurrence O(log n) on sorted array
qaalgosalgosqa - Multiple ChoiceBeginner
[Algorithms] Rotated array O(log n) on sorted array
qaalgosalgosqa - Multiple ChoiceHard
[Algorithms] Search Ordered tree structure
qaalgosalgosqa - Multiple ChoiceHard
[Algorithms] Insert Ordered tree structure
qaalgosalgosqa - Multiple ChoiceHard
[Algorithms] Successor Ordered tree structure
qaalgosalgosqa - Multiple ChoiceHard
[Algorithms] Delete Ordered tree structure
qaalgosalgosqa - Multiple ChoiceHard
[Algorithms] Balance Ordered tree structure
qaalgosalgosqa - Multiple ChoiceHard
[Algorithms] Priority queue Single-source shortest path
qaalgosalgosqa - Multiple ChoiceHard
[Algorithms] Relaxation Single-source shortest path
qaalgosalgosqa - Multiple ChoiceHard
[Algorithms] Negative edges Single-source shortest path
qaalgosalgosqa - Multiple ChoiceHard
[Algorithms] vs A* Single-source shortest path
qaalgosalgosqa - Multiple ChoiceHard
[Algorithms] Dial's algorithm Single-source shortest path
qaalgosalgosqa - Multiple ChoiceHard
[Algorithms] Top-down Subproblem memoization
qaalgosalgosqa - Multiple ChoiceHard
[Algorithms] Bottom-up Subproblem memoization
qaalgosalgosqa - Multiple ChoiceHard
[Algorithms] Knapsack Subproblem memoization
qaalgosalgosqa - Multiple ChoiceHard
[Algorithms] LCS Subproblem memoization
qaalgosalgosqa - Multiple ChoiceHard
[Algorithms] Optimal substructure Subproblem memoization
qaalgosalgosqa - Multiple ChoiceIntermediate
[Algorithms] Coin change Locally optimal choice
qaalgosalgosqa
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