## [solution] Luogu-P4774 [NOI2018] Dragon Slayer

If you fight with a dragon for too long, you will become a dragon. If you stare at the abyss too long, the abyss will stare back.
-- Nietzsche's the other side of good and evil
P4774 [NOI2018] Dragon Slayer
Description
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Description
Players ...

Posted on *Fri, 03 Dec 2021 09:41:15 -0500* by **wint.thaw**

## Fast Fourier Transform (FFT) Essays

Finally, I learned FFT and recorded a piece of water with my notes
There are a lot of things on the front-end knowledge network, so let's not go into details here, just get to the point
01 Introduction to FFT
This only points out the general application of FFT in competition, that is, optimizing polynomial multiplication
Generally, calculatin ...

Posted on *Thu, 02 Dec 2021 13:23:00 -0500* by **sprocket**

## Code works round #756 (Div. 3)

Code works round #756 (Div. 3)
[1611A]. Make Even
Idea: there are only four cases. If the last person is even, you need to
0
0
0 times; Otherwise, if the first bit is even, just reverse the whole, and
1
...

Posted on *Sun, 28 Nov 2021 06:17:13 -0500* by **coldkill**

## Junjun algorithm class - Fundamentals of number theory

catalogueFundamentals of number theoryto be divisible byCounting gcdPei Shu theoremapplicationextended euclidean algorithm Algorithm descriptionlcmcongruencenatureapplicationInverse elementEratoseni sieve methodDu Jiao sieveLagrange interpolationSun Tzu theoremproveconclusiontext
Fundamentals of number theory
to be divisible by
For two integers ...

Posted on *Sat, 06 Nov 2021 15:05:02 -0400* by **bschwarz**

## Noip simulation 90 2021.11.5 (longest problem solution)

T1 palindrome
This classic \ (dp \) just can't do it, just can't.....
Except for the \ (dp \) array, everything else is similar to the problem solution, but it's useless....
Let \ (dp[len][x1][x2] \) mean that half the length of the palindrome string is \ (len \), the abscissa of the end point of the string starting from \ ((1,1) \) is \ (x1 \) ...

Posted on *Fri, 05 Nov 2021 22:34:25 -0400* by **aouriques**

## On Du Jiao sieve

Today, I want to learn Mobius inversion, and then there is a problem that needs Du Jiao sieve in the problem list, and I pushed it to the place where there is only Du Jiao sieve left
So I had to learn this fairy algorithm. I really had to....
Du Jiao sieve is an advanced algorithm for prefix sum of quadrature functions below linear complexity, ...

Posted on *Sun, 31 Oct 2021 17:47:59 -0400* by **tartou2**

## Selected miscellaneous questions (Fate Trilogy)

How difficult it is to find three questions about \ (fat \) in a world full of cadoli
Today's meal at Emiya's house
A very good inclusion exclusion + \ (dp \) problem
Considering the third limitation, it is found that at most one column is illegal, so we can enumerate which column is illegal
Then the next task is to find the total number of sch ...

Posted on *Thu, 28 Oct 2021 18:47:03 -0400* by **newbiehacker**

## Summary of Math built-in object knowledge in JS

Summary of Math built-in object knowledge in JS
5.4.2 Math
The Math object serves as a place to store mathematical formulas, information, and calculations. Some properties and methods of auxiliary calculation are provided.
note: Math objects provide much faster calculations than those implemented directly in JavaScript, ...

Posted on *Fri, 22 Oct 2021 03:46:23 -0400* by **Oren**

## leetcode brush Title records day024:20 and 118

20. Easy to use: 45% pass rate
Method 1: Origin: Failed Violence: For my own future review, there are all kinds of situations that I did not think of at first but follow up and corresponding responses
Principle: Normally judge if the current item and the next item are a bunch of parentheses, and add the response of the left parentheses group ...

Posted on *Tue, 12 Oct 2021 15:49:40 -0400* by **vronsky**

## leetcode brush record day021:326 and 204

326. Simple difficulty:
Requirement: do not use loops or recursion to complete the problem Note: 0 times of 3 = 1, which also needs to be taken into account.
Method 1: Trial Division: time complexity: O(log n) space complexity: O(1)
We keep dividing n by 3 until n=1. If n cannot be divided by 3 in this process, it means that n is not a power ...

Posted on *Sat, 09 Oct 2021 03:28:21 -0400* by **rubbertoad**