哈希·表·结合·design 模式

识别信号

• Check if the candidate correctly uses hash tables for efficient frequency management.
• Evaluate the approach for handling multiple operations efficiently under large constraints.

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 handle cases where a number's frequency drops to zero after a delete operation.