Merge pull request #33 from programmingbookclub/40-2022-0308-Heap-3nd

Create 40 2022 0308 Heap 3nd.md

Author: the-yuyut

紀錄/40 2022 0308 Heap 3nd.md

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+# LeetCode 讀書會第 40 次聚會 2022/03/08
+
+## leetcode 讀書會通知
+
+1. 項目: 第 40 次聚會
+2. 目的: 線上一起寫題目, 由有想法的人帶領, 先解題, 再看該題有趣的解法
+3. 時間: 03/08 (二) 20:00 ~ 21:00
+4. 地點: google meet 線上 (前 10 分鐘預備鏈接)
+5. 解題項目:  [Heap](https://leetcode.com/explore/featured/card/heap/643/heap/)
+6. 共筆: GitHub https://github.com/programmingbookclub/Leetcode-club
+7. 備註: 
+
+這次會強調嘗試 Binary Heap 從無到有的實作，從 347 開始。
+
+
+--- 
+
+* 	[done] MEDIUM	215	Kth Largest Element in an Array	https://leetcode.com/problems/kth-largest-element-in-an-array
+* 	MEDIUM	347	Top K Frequent Elements	https://leetcode.com/problems/top-k-frequent-elements
+* 	EASY	703	Kth Largest Element in a Stream	https://leetcode.com/problems/kth-largest-element-in-a-stream
+* 	EASY	1046	Last Stone Weight	https://leetcode.com/problems/last-stone-weight
+* 	EASY	1337	The K Weakest Rows in a Matrix	https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix
+* 	MEDIUM	378	Kth Smallest Element in a Sorted Matrix	https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix
+* 	🔓	MEDIUM	253	Meeting Rooms II	https://leetcode.com/problems/meeting-rooms-ii
+* 	MEDIUM	973	K Closest Points to Origin	https://leetcode.com/problems/k-closest-points-to-origin
+* 	🔓	MEDIUM	1167	Minimum Cost to Connect Sticks	https://leetcode.com/problems/minimum-cost-to-connect-sticks
+* 	MEDIUM	1642	Furthest Building You Can Reach	https://leetcode.com/problems/furthest-building-you-can-reach
+* 	HARD	295	Find Median from Data Stream	https://leetcode.com/problems/find-median-from-data-stream
+
+---
+
+- 從 Array 建立起 Heap 的時間複雜度
+	- Foreach => O(N LogN)
+	- Heapify => O(N)
+- No. 347. Top K Frequent Elements 解法
+	- 算出每個數字的頻率後，把頻率表放進 heap
+	- 使用 Bucket Sort