string·结合·字典树 模式

识别信号

• The candidate should demonstrate a strong grasp of string manipulation techniques like Trie usage and rolling hashes.
• Look for understanding of how to handle distinct substrings efficiently.

解题流程

1. 1. 明确窗口/状态定义
2. 2. 更新状态并维护约束
3. 3. 用边界样例验证

常见失分点

• Failing to account for overlapping substrings that are distinct but share characters, which can lead to incorrect results.