math plus rejection sampling Pattern
1 problems
Pattern pages help build reusable solving frames. Identify signals first, then explain state, transition, and edge handling.
Recognition Signals
- Will your solution maintain uniform distribution for all outputs?
- How can you reduce the expected number of rand7() calls in your mapping?
Solve Flow
- 1. Define the active state/window.
- 2. Update state while preserving invariants.
- 3. Validate with edge-heavy examples.
Common Misses
- Using rand7() % 10 directly introduces bias.