[置頂]ECDSA

什麼是ECDSA?

黑柴犬與玩具tiger 1戰車

Py3 C++ DP速解1320 Minimum Distance to Type a Word Using Two Fingers

Py3 C++ DP速解1320  Minimum Distance to Type a Word Using Two Fingers

這題確實有難度，最初的解答是3D DP，然後逐次化簡，化成2D後，大該就已經是極致了，不想用hash map，300x (26+1)也不大，0ms C++ code

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This problem is indeed challenging. The initial solution was 3D dynamic programming, which was then simplified to 2D, reaching its limit. I didn't want to use a hash map; 300x (26+1) isn't a large number. 0ms C++ code.

[codes on Leetcode]https://leetcode.com/problems/minimum-distance-to-type-a-word-using-two-fingers/solutions/7876562/2d-dp-reduced-spacebeats-100-by-anwenden-0lk6/

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 

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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

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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/