Challenge Library
Coding Challenges
5,893 curated questions across every arena — browse by topic, then jump into a live 3-minute battle to put them to the test.
Filter by type
Filter by difficulty
Popular topics
528 challenges matching your filters
- Code AnalysisBeginner
Trace: Status Code Choice
backendanalysisbeginner - Code AnalysisBeginner
REST pagination response
backendbeginner - Code AnalysisBeginner
OpenAPI path spec
backendbeginner - Code AnalysisBeginner
Health check response
backendbeginner - Code AnalysisBeginner
Bearer token in header
backendbeginner - Code AnalysisBeginner
Redis SET with EX
backendbeginner - Code AnalysisBeginner
Cache-Control header
backendbeginner - Code AnalysisBeginner
DISTINCT clause
backendbeginner - Code AnalysisBeginner
Status code match
backendbeginner - Code AnalysisBeginner
Query params Express
backendbeginner - Code AnalysisBeginner
Path params Express
backendbeginner - Code AnalysisBeginner
JSON response
backendbeginner - Code AnalysisBeginner
DNS record types
backendbeginner - Code AnalysisBeginner
CI pipeline trigger
backendbeginner - Code AnalysisBeginner
Log level filter (Analysis)
backendbeginner - Code AnalysisBeginner
Structured log entry
backendbeginner - Code AnalysisBeginner
gzip size reduction
backendbeginner - Code AnalysisBeginner
Batch vs individual
backendbeginner - Code AnalysisBeginner
Unit test example
backendbeginner - Code AnalysisBeginner
Assertion failure
backendbeginner - Code AnalysisBeginner
Trace: Integer Division
canalysisbeginner - Code AnalysisBeginner
Trace: Array Index
canalysisbeginner - Code AnalysisBeginner
Trace: Array Access
canalysisbeginner - Code AnalysisBeginner
Trace: Bitwise AND
canalysisbeginner - Code AnalysisBeginner
Trace: Bitwise OR
canalysisbeginner - Code AnalysisBeginner
Trace: Left Shift
canalysisbeginner - Code AnalysisBeginner
Trace: Break
canalysisbeginner - Code AnalysisBeginner
Trace: Char Arithmetic
canalysisbeginner - Code AnalysisBeginner
Trace: Continue
canalysisbeginner - Code AnalysisBeginner
Trace: Integer Division — Negative
canalysisbeginner - Code AnalysisBeginner
Trace: Float Cast
canalysisbeginner - Code AnalysisBeginner
Trace: Float Division
canalysisbeginner - Code AnalysisBeginner
Trace: Mixed Types
canalysisbeginner - Code AnalysisBeginner
Trace: Float Multiply
canalysisbeginner - Code AnalysisBeginner
Trace: For Loop
canalysisbeginner - Code AnalysisBeginner
Trace: Increment in Printf
canalysisbeginner - Code AnalysisBeginner
Trace: Logical AND
canalysisbeginner - Code AnalysisBeginner
Trace: Modulo
canalysisbeginner - Code AnalysisBeginner
Trace: Unary Negation
canalysisbeginner - Code AnalysisBeginner
Trace: Parentheses
canalysisbeginner - Code AnalysisBeginner
Trace: Post-Increment
canalysisbeginner - Code AnalysisBeginner
Trace: Pre-Increment
canalysisbeginner - Code AnalysisBeginner
Trace: Operator Precedence
canalysisbeginner - Code AnalysisBeginner
Trace: Address Of (basic)
canalysisbeginner - Code AnalysisBeginner
Trace: Array as Pointer
canalysisbeginner - Code AnalysisBeginner
Trace: Pointer Index
canalysisbeginner - Code AnalysisBeginner
Trace: Null Pointer
canalysisbeginner - Code AnalysisBeginner
Trace: Sizeof Array
canalysisbeginner - Code AnalysisBeginner
Trace: Sizeof Int
canalysisbeginner - Code AnalysisBeginner
Trace: Strlen
canalysisbeginner - Code AnalysisBeginner
Trace: Ternary
canalysisbeginner - Code AnalysisBeginner
Trace: While Loop
canalysisbeginner - Code AnalysisBeginner
Trace: printf int
canalysisbeginner - Code AnalysisBeginner
Trace: Address of (advanced)
canalysisbeginner - Code AnalysisBeginner
Trace: Dereference — Multi-level
canalysisbeginner - Code AnalysisBeginner
Trace: sizeof
canalysisbeginner - Code AnalysisBeginner
Bitwise AND
code-analysisClanguage - Code AnalysisBeginner
Comma Operator
code-analysisClanguage - Code AnalysisBeginner
Double to Int
code-analysisClanguage - Code AnalysisBeginner
Null Pointer Print
code-analysisClanguage
Practice now, dominate the arena
Every challenge here is drawn from the live Code Royale pool. Review a question, then head to the arena to answer under pressure against a real opponent — 3-minute matches, Elo ranking, and badge tiers on the line.