30-day review index
Review the first family in a compact cheatsheet. Remaining family previews are clearly marked Pro only.
Pattern-first interview review
PrepStack
Algorithm Patterns
把算法题压缩成可迁移、可复习的模板系统。Free 包含首个 pattern family 与 LC 1–100；Pro 解锁完整知识库。
Knowledge base
Open the first pattern family, its related problems, and LC 1–100.
Learning graphs
Explore the first family map and see which additional graph views unlock with Pro.