识别信号
- The candidate should demonstrate an understanding of recursive string manipulation techniques.
- Look for the candidate's ability to handle special substring identification and swapping in a recursive manner.
- Notice how recursion mirrors both reversing and inverting previous strings.
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
- Failing to identify the correct substrings for swapping can lead to incorrect results.
- Attempting to construct the entire S_n, leading to exponential memory use.