C++C py3 log4 prefix sum, bits解Leetcode難題3495 Minimum Operations to Mak...

C++C py3 log4 prefix sum/bits解Leetcode難題3495  Minimum Operations to Make Array Elements Zero

ceil(log4(x)) 可以透過 clz 計算；將 expSum 定義為部分和來計算。

[Py3 code請進]

C++ C Py3 Rust數bits解Leetcode 2749 Minimum Operations to Make the Intege...

C++ C Py3 Rust數bits解Leetcode 2749  Minimum Operations to Make the Integer Zero

[Py3解請進]

Py3 C++排序loop解Leetcode 3025 3027 Find the Number of Ways to Place People

Py3 C++排序loop解Leetcode 3025 3027 Find the Number of Ways to Place People

[Py3 code請進]

C++回遡與bitmask解Leetcode 37數獨Sudoku

C++回遡與bitmask解Leetcode 37數獨Sudoku

有些經典問題值得一解再解，雖然不是最佳解，也要比Leetcode Editorial的解有效許多。解數獨，回遡乃基本款，但加上bitmask就能篩掉許多無用的測試，就更快許多

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Some classic problems are worth solving again and again. Although they are not the best solutions, they are much more effective than Leetcode Editorial's solutions. Solve Sudoku by using backtracking is the basic version, but add bitmask to filter out many useless tests can make it much faster.

[codes on Leetcode]https://leetcode.com/problems/sudoku-solver/solutions/7139967/new-sol-bitmask-backtracking-beats-100/

[其他採回溯未用bitmask解法]https://www.youtube.com/watch?v=wviWrbbOdYE

Py3 C++速解Leetcode 3446 Sort Matrix by Diagonals/with Py3 code

Py3 C++速解Leetcode 3446  Sort Matrix by Diagonals

矩陣問題都是很好的迴圈、陣列練習，又加上排序那就是很好的練習題

[Py3 code請進]

C++ dp動態規劃解Leetcode 3459 Length of Longest V Shaped Diagonal Segment

C++ dp動態規劃解Leetcode 3459  Length of Longest V Shaped Diagonal Segment

採DP動態規劃迭代版本解難題，需要定義V-shaped distance

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Using the DP dynamic programming iterative version, it is necessary to define the V-shaped distance

[codes on Leetcode]https://leetcode.com/problems/length-of-longest-v-shaped-diagonal-segment/solutions/7126168/dp-recursive-dfs-or-iteration-beats-100/

[DP動態規劃Playlist]https://www.youtube.com/watch?v=30yq3fmE6E8&list=PLYRlUBnWnd5K_XYUesV9oc6M9ONXII61T

Py3 C++畢氏定理速解Leetcode 3000 Maximum Area of Longest Diagonal Rectangle

Py3 C++畢氏定理速解Leetcode 3000  Maximum Area of Longest Diagonal Rectangle

Py3 C++ Pythagorean Theorem Quick Solution Leetcode 3000 Maximum Area of​​ Longest Diagonal Rectangle

[codes on Leetcode]https://leetcode.com/problems/maximum-area-of-longest-diagonal-rectangle/solutions/7122597/easy-1-pass-vs-max-with-custom-cmp-c-py3-beats-100/

[Leetcode playlist]https://www.youtube.com/watch?v=VfRVKO7El9w&list=PLYRlUBnWnd5IdDHk2BjqXwesydU17z_xk

Py3 C++ sliding window速解Leetcode1493 Longest Subarray of 1's After Dele...

Py3 C++ sliding window速解Leetcode1493  Longest Subarray of 1's After Deleting One Element

示範如何從一般  sliding window解答簡化成單迴圈解答解無if

[Py3解在此，請進]

C++bitmask陣列切割解Leetcode難題3197 Find the Minimum Area to Cover All Ones II

C++bitmask陣列切割解Leetcode難題3197  Find the Minimum Area to Cover All Ones II

這是個立方時間的解答，主要採bitmask陣列法表達矩陣，應該沒人這樣做，最快時間已達8ms擊敗100%的C++參與者。

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This is a cubic time solution, which mainly uses the bitmask array method to express the matrix. It is unlikely that anyone would do this. The fastest time has reached 8ms, beating 100% of the C++ participants.

[codes on Leetcode]https://leetcode.com/problems/find-the-minimum-area-to-cover-all-ones-ii/solutions/7111740/bitmask-1d-array-for-grid-its-transpose-deal-with-6-cases-8ms-beats-100/

C++ dp動態規劃速解Leetcode 1277 Count Square Submatrices with All Ones

C++ dp動態規劃速解Leetcode 1277  Count Square Submatrices with All Ones

使用matrix當成state matrix

[codes on Leecode]https://leetcode.com/problems/count-square-submatrices-with-all-ones/solutions/7101478/reuse-matrix-as-state-matrix-beats-100/

[DP play list]https://www.youtube.com/watch?v=30yq3fmE6E8&list=PLYRlUBnWnd5K_XYUesV9oc6M9ONXII61T

Py3 C++陣列迴圈速解Leetcode 1323 Maximum 69 Number

Py3 C++陣列迴圈速解Leetcode 1323  Maximum 69 Number

學程式的第一式，就是要會活用陣列迴圈，足以解Leetcode 1323. Maximum 69 Number 

[Py3解請進]

Leetcode 342 Power of Four幾個C++一行解

Leetcode 342  Power of Four幾個C++一行解

[codes on Leetcode]https://leetcode.com/problems/power-of-four/solutions/7081839/9-ways-of-bit-manipulation-1-liner-beats-100/

[bit/ bitmask playlist]https://www.youtube.com/watch?v=Hw1fnQA8Nk8&list=PLYRlUBnWnd5K8FlzJ6tOswqQcsk7R1Duh

C++一行解Leetcode 326 Power of Three

C++一行解Leetcode 326  Power of Three

利用3的羃次方的因數也是3的羃次方，導出一行C++程式碼

[解答請進]

C++快速模指數計算與prefix sum解Leetcode 2438 Range Product Queries of Powers

C++快速模指數計算與prefix sum解Leetcode 2438  Range Product Queries of Powers

先用fast modular exp解Leetcode 2438. Range Product Queries of Powers，這不會殺雞用牛刀?

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First, use fast modular exp to solve Leetcode 2438. Range Product Queries of Powers. This will not be an overkill?

[codes on Leetcode]https://leetcode.com/problems/range-product-queries-of-powers/solutions/7066112/fast-modular-exp-prefix-sum-dp-precompute-beats-100/

C++ DP速解難題leetcode 3363 Find the Maximum Number of Fruits Collected/Py3 code inclusive

C++ DP速解難題leetcode 3363  Find the Maximum Number of Fruits Collected

[Python解請進]

segment tree C++解Leetcode 3479 Fruits Into Baskets III

segment tree C++解Leetcode 3479  Fruits Into Baskets III

線段樹(segment tree)是一種進階的資料結構，可以用來解決一些 LeetCode 難題。

線段樹本質上是一棵二元樹；它可以用二元樹來實現，但更常見的是使用陣列表示。這題需要用到有最大值的線段樹；以及一種尋找第一個不小於target的basket然後更新的方法。

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Segment tree is an advance data struture which can solve several Leetcode questions.

Segment tree is basically a binary tree, ; it can be implemented by using binary tree, but most frequently its array representation way. This question needs the segment tree with max; and a method which  searchs the 1st basket not less than target & then updates it.

[Solution to  3477  Fruits Into Baskets II]https://leetcode.com/problems/fruits-into-baskets-ii/solutions/7045085/easy-subtraction-beats-100/

二元搜尋sliding window C++ py3解Leetcode 2106難題Maximum Fruits Harvested After ...

二元搜尋sliding window cpp py3解Leetcode 2106難題Maximum Fruits Harvested After at Most K Steps

[C++ solution請進]

Py3 C++奇偶交錯奇偶子數列解Leecode 3201 Find the Maximum Length of Valid Subsequ...

Py3  C++奇偶交錯奇偶子數列解Leecode 3201  Find the Maximum Length of Valid Subsequence I

求最長有效子序列，使得 (sub[0] + sub[1]) % 2 == (sub[1] + sub[2]) % 2 == ... == (sub[x - 2] + sub[x - 1]) % 2，有 3 種可能的情況

-全為偶數

-全為奇數

-或奇偶交錯子序列

[Py3解請進]

Py3 C++母音 vowel mask速解Leetcode 3136 Valid Word

Py3 C++母音 vowel mask速解Leetcode 3136  Valid Word

Leetcode有許多判斷母音的問題，採用bitmask方式，迅速又方便

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Leetcode has many problems in determining vowels. Using the bitmask method is fast and convenient.

[codes onLeetcode]https://leetcode.com/problems/valid-word/solutions/6959558/bitmask-for-vowel-bitset-beats-100/

C++ Py3 hashmap與binary search解Leetcode 1865 Finding Pairs With a Certain...

C++ Py3 hashmap與binary search解Leetcode 1865 Finding Pairs With a Certain Sum

基本上用 hashmap。解釋為什麼要使用排序和二元搜尋找來優化程式碼

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Basically use hashmap. Explain why  one should use sorting and binary search to optimize the code.

[codes on Leetcode]https://leetcode.com/problems/finding-pairs-with-a-certain-sum/solutions/6925404/unordered-map-sort-binary-search-c-37ms-99-37-py3-97-45/

[Leetcode playlist]https://www.youtube.com/watch?v=LJPL-Ukxf8w&list=PLYRlUBnWnd5IdDHk2BjqXwesydU17z_xk

Py3 C++位元計算bitset速解Leetcode難題3307 Find the K th Character in String Gam...

Py3 C++位元計算bitset速解Leetcode難題3307  Find the K th Character in String Game II

[Py3 一行解請進]

Py3排序 C++nth_element速解Leetcode 2099 Find Subsequence of Length K With t...

Py3排序 C++nth_element速解Leetcode 2099  Find Subsequence of Length K With the Largest Sum

C++的nth_element很好用，基本上是做partition，在這個問題可取代sort

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C++'s nth_element is very useful. It basically does partitioning and can replace sort in this problem.

[codes on Leetcode]https://leetcode.com/problems/find-subsequence-of-length-k-with-the-largest-sum/solutions/6893606/nth-element-counting-sort-c-100-py3-1-line/

Py3 C++計數排序counting sort解Leetcode 2294 Partition Array Such That Maximu...

Py3 C++計數排序counting sort解Leetcode 2294  Partition Array Such That Maximum Difference Is K

基本上使用Greedy sort，而排序就用counting sort

[Python C++計數排序與一行解Leetcode 1051 Height Checker]https://www.youtube.com/watch?v=dybiq3pg-Os

[ Leetcode play list]https://www.youtube.com/playlist?list=PLYRlUBnWnd5IdDHk2BjqXwesydU17z_xk

2025資訊安全Steganography隱寫術Python實作

Py3 C++ DFS解Leetcode難題1298 Maximum Candies You Can Get from Boxes

Py3 C++ DFS解Leetcode難題1298  Maximum Candies You Can Get from Boxes

[codes on Leetcode]https://leetcode.com/problems/maximum-candies-you-can-get-from-boxes/solutions/6805859/dfs-bfs-for-a-tree-beats-100/

[Tree/graph list]https://www.youtube.com/watch?v=vdar3a_ZdCI&list=PLYRlUBnWnd5Kt0-3un43cwY6yT_il8NWe

C++Py3重複組合排容原理解Leetcode2929 Distribute Candies Among Children II

C++Py3重複組合排容原理解Leetcode2929  Distribute Candies Among Children II

Use combinatorial number with repetition & Inclusion-Exclusion Prinple to solve

[Py3解請進]

C++ DFS BFS解答Leecode難題3373 Maximize the Number of Target Nodes After Co...

C++ DFS BFS解答Leecode難題3373  Maximize the Number of Target Nodes After Connecting Trees II

圖論問題，跟bipartite有關

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Graphic question is related to the bipartite.

[codes on Leecode]https://leetcode.com/problems/maximize-the-number-of-target-nodes-after-connecting-trees-ii/solutions/6791084/dfs-bfs-with-parity-bitset-beats-100/

[Tree & Graph ]https://www.youtube.com/watch?v=vdar3a_ZdCI&list=PLYRlUBnWnd5Kt0-3un43cwY6yT_il8NWe

2025 AES 像素pixel加密圖檔解密

2025 C++ opencv卷積計算與影像處理

C++ Py3計數解Leetcode 2131 Longest Palindrome by Concatenating Two Letter ...

C++ Py3計數解Leetcode 2131  Longest Palindrome by Concatenating Two Letter Words

回文問題常被問到。這題基本上可以用計數的方法來解決。重點是兩個字母的字串 xy 和 yx 可以配對。

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Palindrome question is quite often asked. This question can be solved basically by using counting. It's important to know the 2-letter strings xy & yx can be paired.

[codes on Leetcode]https://leetcode.com/problems/longest-palindrome-by-concatenating-two-letter-words/solutions/6778069/2d-array-counter-freq-count-c-c-py3-beats-100/

[C, C++ ,python速解迴文Leetcode 2108 Find First Palindromic String in the Array]https://www.youtube.com/watch?v=eXhdv8jDpao

C++ opencv selectROI擷圖與馬賽克

2025 AES opencv python圖檔加密

opencv C++使用卷積convolution/correlation進行影像處理

 

 opencv C++使用卷積convolution/correlation進行影像處理 

C/C++/Py3使用荷蘭旗演算3 pointer解Leetcode 75 Sort Colors

C C++ Py3使用荷蘭旗演算3 pointer解Leetcode 75 Sort Colors

一次走訪演算採用於荷蘭旗演算法。

[Py3解請進]

2025 opencv C++萬用VideoCapture Class

C++ Py3 Greedy 2 pointer速解(含1行解)Leetcode 2900 Longest Unequal Adjacent ...

C++ Py3 Greedy 2 pointer速解2900  Longest Unequal Adjacent Groups Subsequence I

C++ 會採用 2 -pointers主要的原因，就是不要額外的陣列，達到真正的O(1)空間解。

[Py3一行解請進]

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AES 256文字加密python實作

2025簡易opencv C++色階、負片處理

C++ Py3 Greedy速解Leetcode 2918 Minimum Equal Sum of Two Arrays After Rep...

C++ Py3 Greedy速解Leetcode 2918  Minimum Equal Sum of Two Arrays After Replacing Zeros

影片展示如何使用C++ STL編寫一個簡短的C++解答； Python程式碼也是按照類似的方式完成的。

[Py3 code請進]

python模擬Diffie Hellman金鑰交換與淺談量子電腦Shor演算攻擊

python requests股市爬蟲與pyplot數據視覺化操作

Python code如下:

2025安裝C++ opencv與測試秀圖

2025 RSA演算 python實作加密解密

C++ OOP洗牌解Leetcode 384 Shuffle an Array

C++ oop洗牌解Leetcode 384  Shuffle an Array

[codes on Leetcode]https://leetcode.com/problems/shuffle-an-array/solutions/6676446/stl-shuffle-vs-fisher-yates-algorithm/

[C++洗牌shuffle與Fisher Yates演算, 大樂透開獎]

python單一迴圈解答最佳股票的買賣時機LeetCode 121 Best Time to Buy and Sell Stock

先說明一下這是後知後覺的解答，所謂後知就是股票價格已知存在陣列(清單)，當然就要用迴圈練習，雙迴圈暴力解需時O(n**2)，當然不用，採python單一迴圈解答「最佳股票的買賣時機#LeetCode 121  Best Time to Buy and Sell Stock」，解法簡單快速O(n)時間。

C++ Py3計數解Leetcode 781 Rabbits in Forest

C++ Py3計數解Leetcode 781 Rabbits in Forest

[codes on Leetcode]https://leetcode.com/problems/rabbits-in-forest/solutions/6668360/group-numbers-with-x-at-most-size-x-1-1-liner-beats-100/

[Python C++計數速解Leetcode 945 Minimum Increment to Make Array Unique]https://www.youtube.com/watch?v=tS-kunvQwcc

C++ class物件導向初探與實作

python版教科書級RSA產生key

有些版次的車輪沒造好，就自己造，以下為教科書版能處理1024-bit RSA的python程式

C++用mt19937虛擬亂數、不同機率分佈與求圓周率

C++用C rand虛擬亂數、陣列及萬用標頭檔使用

2025安裝wireshark並抓ICMP封包

網路安全與Wireshark測驗解答

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資安威脅與惡意軟體測驗檢討與wireshark解讀http封包中密碼

C++作業Leetcode 70 Climbing Stairs爬樓梯fibonacci費氏數列動態規劃實作

Fibonacci費式數列、Leetcode 70爬樓梯與動態規劃

C++小考檢討與fibonacci費氏數列top down設計實作

C++作業遞迴函數實作fibonacci費氏數列於Colab, Leetcode Visual studio與Python版比較

C++遞迴函數與fibonacci費氏數列

C++ Py3 Sliding window速解Leetcode 2379 Minimum Recolors to Get K Consec...

C++ Py3  Sliding window速解2379  Minimum Recolors to Get K Consecutive Black Blocks

[Py3 解含過程輸出請進]

Py3 C++算術數列算面積一行解Leetcode 2579 Count Total Number of Colored Cells

Py3 C++算術數列算面積一行解Leetcode 2579  Count Total Number of Colored Cells

利用算術數列面積公式一行解Leetcode 257

[Py3解請進]

模仿遊戲enigma納粹密碼機與cryptool2破解the code book相關密碼2

模仿遊戲enigma納粹密碼機與cryptool2破解the code book相關密碼1

C++ prefix sum Kadane Python一行解Leetcode 1749. Maximum Absolute Sum of An...

cpp prefix sum Kadane Python一行解Leetcode 1749. Maximum Absolute Sum of Any Subarray

[解答請進]

C++py3排列組合與binary表達解Leetcode 1415 The k th Lexicographical String of Al...

C++py3排列組合與binary表達解Leetcode 1415  The k th Lexicographical String of All Happy Strings of Length n

總共有3*2^(n-1)個happy strings要求第k個。先算(k-1)除以2^(n-1)的商q與餘數r，s[0]由q決定，s[1:n]由r決定，化r為二進位，然後簡單處理一下就得解

[Py3解請進]

C++ Py3 reverse 2pointer解Leetcode 2375 Construct Smallest Number From D...

C++ Py3 reverse 2pointer解Leetcode 2375  Construct Smallest Number From DI String

[codes on Leetcode]https://leetcode.com/problems/construct-smallest-number-from-di-string/solutions/6435240/suffix-sum-for-successive-ds-c-py3-beats-100/

C++ OOP Prefix Product解Leetcode 1352 Product of the Last K Numbers

C++ OOP Prefix Product解Leetcode 1352  Product of the Last K Numbers

Leetcode這題1352. Product of the Last K Numbers，是很好的OOP題目，除了談談class之外，還能練習一下prefix product的概念(與prefix sum類似但要小心0)

[C++解請進]

如何在colab上撰寫C++程式

Python C++ hashmap解Leetcode 3160 Find the Number of Distinct Colors Am...

Python C++  hashmap解Leetcode 3160  Find the Number of Distinct Colors Among the Balls

嘗試2個hashmap來解決。由於實際運行，可以說，Python dict 比 C++ unordered_map 快得多

[Py3 code請進]

排列組合Python解Leetcode 1726 Tuple with Same Product

本片展示如何理解這題排列組合實質內容，以及如何完成 1 行Python程式碼。

[Py3 code請進]

Python C++單迴圈速解Leetcode 3105 Longest Strictly Increasing or Strictly De...

Python cpp單迴圈速解Leetcode 3105  Longest Strictly Increasing or Strictly Decreasing Subarray

用單迴圈就可解，甚至也沒有用到if, switch, tenary

[Py3解請進]

C++ UnionFind解難題Leetcdoe 827 Making A Large Island(含Py3解)

C++ UnionFind解難題Leetcdoe 827  Making A Large Island

嘗試UnionFind解決。由於該題目透過最多翻轉 1 個額外的 0 單元來詢問最大島嶼的大小；使用Size優化而不是rank。

[Python解請進]

Python C++BFS /heap解Leetcode難題407 Trapping Rain Water II

Py3 cpp BFS /heap解Leetcode難題407 Trapping Rain Water II

解題要訣:boundary由外而內，容器採min heap，BFS走訪

[Py3解請進]

Python C++速解Leetcode迴文1400 Construct K Palindrome Strings

Python C++速解Leetcode迴文1400  Construct K Palindrome Strings

關鍵：偶數長度的回文字串中所有字母都出現偶數，奇數長度的回文字串中除了一個例外其他所有字母都出現偶數。

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The key observation: palindrome strings of even lengths have all letters even occurrences, palindrome strings of odd lengths have all letters even occurrences but except one letter with odd occurrence.

[Py3解答請進]

C++ python 用Prefix Sum速解Leetcode 2270 Number of Ways to Split Array

Prefix sum這個概念，只要數學會用Sigma的，問題都不大，基本上就是partial sum。程式要寫的好，老實講該有數學概念真不能少，演算法的東西畢竟是真刀真槍的。

C++ python 用Prefix Sum速解Leetcode 2270  Number of Ways to Split Array

求分割陣列 nums 的方式數量，使得 sum(nums[0...i]) \geq sum(nums[i+1...])。

如何？計算總和sum=sum(nums)

使用loop判斷i是否滿足sum(nums[0..i])\geq sum(nums[i..])=sum-sum(nums[0..i])

「Py3解請進」