🔄 复习日 / Review Day
今天是复习日！回顾过去4天的内容。
📝 Quick Quiz — 3 Mini-Reviews
Pick 3 topics from 3 different sections.
Q1: [🏗️ System Design] 在设计分布式唯一ID生成器（如 Twitter Snowflake）时，为什么时间戳部分通常放在最高位（最左边）？ / When designing a distributed unique ID generator (like Twitter Snowflake), why is the timestamp component usually placed in the most significant bits (leftmost)?
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将时间戳放在高位可以保证生成的ID大致按时间递增（Time-sortable）。这对于数据库索引（如 B+ 树）非常友好，能有效减少页分裂，提高插入性能。 / Placing the timestamp in the most significant bits ensures that the generated IDs are roughly sortable by time. This is highly beneficial for database indexing (like B+ trees) as it reduces page splits and improves insertion performance.
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Q2: [💻 Algorithms] 在解决“有效括号” (Valid Parentheses) 问题时，为什么栈 (Stack) 是最合适的数据结构？ / When solving the "Valid Parentheses" problem, why is a Stack the most appropriate data structure?
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因为括号的匹配遵循“后进先出”（LIFO）的原则。最后遇到的未闭合左括号，必须最先被相应的右括号闭合。栈完美契合了这种处理顺序。 / Because parenthesis matching follows a "Last-In-First-Out" (LIFO) principle. The most recently encountered unclosed left parenthesis must be closed first by a corresponding right parenthesis. A stack perfectly models this order of operations.
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Q3: [🎨 Frontend] 在 React 中，受控组件 (Controlled) 和非受控组件 (Uncontrolled) 处理表单数据的主要区别是什么？ / In React, what is the main difference between Controlled and Uncontrolled components for handling form data?
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受控组件的表单数据由 React 的 state 管理，每次输入都会触发状态更新和重新渲染；而非受控组件的表单数据由 DOM 自身管理，通常使用 ref 在需要时（如提交时）一次性读取值。 / In a Controlled component, form data is managed by React state, and every input triggers a state update and re-render. In an Uncontrolled component, form data is managed by the DOM itself, and values are typically read once using a ref when needed (e.g., on submit).
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💡 复习巩固记忆，螺旋式上升。
📅 明天继续新内容！