reshape data pivot core interview pattern 模式
1 道题目
模式页适合用来建立可复用解题框架。先识别题目特征，再按固定流程解释状态定义、转移和边界。
识别信号
- Do you recognize this as a data reshaping or pivot problem?
- Can you suggest a pandas function that avoids manual aggregation?
解题流程
- 1. 明确窗口/状态定义
- 2. 更新状态并维护约束
- 3. 用边界样例验证
常见失分点
- Forgetting to set the correct index, leading to a misaligned table.