regexEASYMULTIPLE CHOICE
Warm up with email redaction pattern
Easy Regex arena: word boundaries, replacements, and avoiding overmatching
XP reward
95
Coins
8
Target time
15m
Support exports must mask emails while preserving domain-level debugging information. You are working inside a text-processing challenge room, and the arena only clears when the result is safe, deterministic, and explainable.
Learning objective
Learn to apply word boundaries, replacements, and avoiding overmatching in a text-processing challenge room while explaining the invariant, safety constraints, and hidden edge cases.
Mission order
Text contains emails, usernames, URLs, and invalid address-like strings. Implement the direct solution first, then document the one edge case that can break it. Submit the solution plus enough reasoning to pass hidden edge cases.Visible checks
selects the safest option
Expected: B
includes justification
Expected: mentions correctness or risk
Clear requirements
- Demonstrates word boundaries, replacements, and avoiding overmatching
- Handles the visible sample and hidden edge cases
- Keeps output deterministic and explainable
- Avoids unsafe dynamic execution
Secure validation contract
Judge type
MULTIPLE CHOICE
Complexity target
Correct option plus risk-aware explanation
Workspace
Reasoning panel
Test Results
Run the visible checks when your first pass is ready.
Clear Protocol
1Read the scenario and restate the expected output shape.
2Run visible checks before chasing hidden edge cases.
3Use Genie for one nudge if stuck, then explain the invariant.
4Submit only when the result is deterministic and safe.
Rewards
XP
95
Coins
8
Mission Route
Hints
Hints are metered and logged for No Hint Hero runs.
Genie Mentor Core
Hint protocol / contextual guardrails active
Progressive hints
Failed-test aware
Solution guarded
Mission: regex-easy-email-redaction0 attempts0 failed tests0 hints used
Progressive hint depth
Genie: Genie online. I use your mission, attempts, failed tests, hints, and path context to coach the next rep without dumping answers first.