[置頂]ECDSA

什麼是ECDSA?

C++ unordered set PMR解Leetcode 874 Walking Robot Simulation

C++ unordered set PMR解Leetcode 874  Walking Robot Simulation

解Leetcode 874. Walking Robot Simulation因為constraints，只好用hashmap，C++ unordered_set是知名的慢，加上pmr可以快上幾倍 

------

Solving LeetCode 874, Walking Robot Simulation, requires using a hashmap due to constraints. C++'s unordered_set is notoriously slow; adding PMR can speed it up several times.

[codes on Leetcode]https://leetcode.com/problems/walking-robot-simulation/solutions/7789910/hashset-using-pmr4ms-beats-9840-by-anwen-lzym/

黑柴犬走草山水圳AI動畫

黑柴犬與碧潭吊橋meta AI動畫

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/