字典树·driven·solution·strategy 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
- Can the candidate describe a method that avoids iterating through all numbers from 1 to n?
- Did the candidate implement an efficient counting function that works without generating all possible numbers?
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
- Not implementing the Trie structure efficiently, leading to excessive time complexity.