堆・Top-K Heap / Top-K
27 題（14 題以此為主技法）
🎯 何時用
動態取最大／最小、合併多路、第 k 個、中位數、依優先序處理。
🧩 模板心法
大小為 k 的堆維持 Top-K（O(n log k)）；雙堆維持中位數；事件用優先佇列排程。
Easy 2 題
Medium 17 題
- #347Top K Frequent Elements
- #621Task Scheduler
- #355Design Twitter
- #767Reorganize String
- #1405Longest Happy String
- #1834Single Threaded CPU
- #1882Process Tasks Using Servers
- #1985Find the Kth Largest Integer in the Array
- #2542Maximum Subsequence Score
- #253Meeting Rooms II
- #215Kth Largest Element in an Array
- #743Network Delay Time
- #973K Closest Points to Origin
- #1094Car Pooling
- #1514Path with Maximum Probability
- #1631Path with Minimum Effort
- #1845Seat Reservation Manager