[置頂]ECDSA

什麼是ECDSA?

C++UnionFind與matrix分析解難題Leetcode 2573 Find the String with LCP

解難題Leetcode 2573. Find the String with LCP，其實重點是lcp非常特殊的矩陣，只要搞定lcp各項的關聯，如對稱性，對角線上值-1等特性，應該能解出。會先用Union-Find主要是其解法可針對更為廣義的題目，要快就用貪婪。

3D DP minmax解Leetcode 1594 Maximum Non Negative Product in a Matrix

黑柴犬正在操作enigma密碼機

Py3 C++位元處理與DP解Leetcode 1680 Concatenation of Consecutive Binary Numbers

Py3 C++位元處理與DP解Leetcode 1680  Concatenation of Consecutive Binary Numbers

這當然不是DP的問題，但透過DP的手法卻可以大幅減少計算時間

----

This is certainly not a problem with dynamic programming (DP), but by using DP techniques, the computation time can be significantly reduced.

[codes on Leetcode]https://leetcode.com/problems/concatenation-of-consecutive-binary-numbers/solutions/7613841/left-shift-x-with-bitwidth-by-anwendeng-2akl/

人與黑柴狗奔跑

C++ Py3 bitmask速解Leetcode 762 Prime Number of Set Bits in Binary Representation

C++ Py3 bitmask速解Leetcode 762  Prime Number of Set Bits in Binary Representation

這段影片示範如何使用計數位元和位元遮罩(bit mask)，用幾行程式碼解決這個問題。

-----

this video shows how to use count bits & bitmask to solve this question in few lines. 

[codes on Leetcode]https://leetcode.com/problems/prime-number-of-set-bits-in-binary-representation/solutions/7595294/c-bits-count-vs-pascal-trianglebeats-100-2r67/

Py3 C++迴圈與計數解Leetcode 696 Count Binary Substrings

Py3 C++迴圈與計數解Leetcode 696  Count Binary Substrings

Leetcode 696. Count Binary Substrings雖然標示為easy，也沒那麼trivial，花了一番功夫才解出branchless C++。而一般回圈解倒是不難，但須要思考一下

-----

Leetcode 696. Count Binary Substrings, though marked as easy, isn't exactly trivial; it took me some effort to solve it in branchless C++. Solving the general loop problem isn't difficult, but it needs thinking.

[codes on Leetcode]https://leetcode.com/problems/count-binary-substrings/solutions/7590515/cout-the-successive-1s-0sbeats-100-by-an-7amm/

Py3 C++使用 4 hashmaps解Leetcode 3714 Longest Balanced Substring II

 

 不喜歡C++的unordered_map，主要的原因是慢，也不想重新刻一個好的hashmap，不過透過memory_resource中的工具，加快三倍速度，也能寫出簡易的beats 99%C++解答

py3 C++巢狀迴圈解Leetcode難題3640 Trionic Array II

py3 CPP巢狀迴圈解Leetcode難題3640  Trionic Array II

使用巢狀迴圈來解決 LeetCode 上的難題，就用類似解決簡單的題目的方法。

Lettcode 3637. Trionic Array I簡單問題解了，困難的類似題3640. Trionic Array II也用類似方法解了。不要小看怎麼用迴圈