## Enumeration, simulation and sorting

Example: consecutive interval number
Xiao Ming has been thinking about such a strange and interesting question these days:
How many consecutive intervals are there in an arrangement of 1 ∼ N?
The definition of the serial interval here is:
If all the elements in the interval [L,R] (i.e. the L-th to r-th elements of this arrangement) can ...

Posted by **trrobnett** on *Sun, 20 Feb 2022 07:25:50 +0100*

## Introduction to Niuke algorithm Mathematics: 1001-1006 prime numbers

0x00 topic source
Special topics in Mathematics
0x10 Tag
Mathematics, prime, Euler sieve
0x20 1001 prime judgment
Give a number x, judge whether it is a prime number, and output all its prime factors.
0x21 prime sieve (Euler sieve)
The boards are as follows:
bool isnp[MAXN];
vector<int> primes;
void init(int n)
{
for (i ...

Posted by **stonefish** on *Mon, 14 Feb 2022 09:07:33 +0100*

## L3-012 fruit ninja

Title:
Everyone must have played the "fruit ninja" game popular all over the world in 2010? (it doesn't matter if you haven't played ~) in the game, a series of fruits and bombs will be ejected randomly in the screen. Players can complete the tasks specified in the game by cutting off all fruits as much as possible to avoid hitting t ...

Posted by **jexx** on *Tue, 25 Jan 2022 17:24:14 +0100*

## The third special training of HENAU winter camp (Mathematics)

Learning materials related to this training:
Euler function -- the number of Coprime numbers with N in numbers less than n
Game theory and algorithm implementation (three basic games)
Fast power (Java implementation code)
catalogue
A - A^B Mod C
B - inverse element
C - number of decision primes
D - matrix ...

Posted by **patrick99e99** on *Wed, 19 Jan 2022 13:04:41 +0100*

## [number theory series I] C Looooops, checkers, the lucky number, cf906d, power tower, minimum power of prime, guard of honor, LCMSUM

All the number theory knowledge involved below proves portal 1
All the number theory knowledge involved below proves Portal 2
C Looooops
description
solution
Transform the meaning of the question into a mathematical formula
A
+
C
...

Posted by **HektoR** on *Tue, 18 Jan 2022 07:44:38 +0100*

## [Loj #10168. "One book 5.3 exercise 3" hate 7 not to become a wife] solution

Title Link
subject
single!
Still single!
GIGO is still single!
DS code Nong Jige is still single!
Therefore, he hates Valentine's day most in his life. Whether it's \ (214 \) or \ (77 \), he hates it!
GIGO observed the two numbers \ (214 \) and \ (77 \), and found that:
\(2+1+4=7\)
\(7+7=7×2\)
\(77=7 × 11\)
Finally, he found that all this was d ...

Posted by **Garion** on *Thu, 13 Jan 2022 07:48:40 +0100*

## Algorithm template: prime number bucket of number theory (including detailed explanation of Ehrlich sieve method and Euler linear sieve method) [Shen Qi]

preface
Just call me Shen Qi. Recently, I have gained a lot from watching the video of AcWing algorithm basic course. So I decided to open up the algorithm section and officially began to sort out the algorithm notes and clarify my ideas.
This time, we brought prime bucket. Hey, hey. Each part will be matched with the corresponding exerci ...

Posted by **stezz** on *Sat, 08 Jan 2022 13:17:40 +0100*

## luogu5400 CTS2019 random cube

meaning of the title
n
×
m
×
l
n\times m\times l
n × m × l lattice cubes, filled randomly
1
1 ...

Posted by **rn14** on *Mon, 27 Dec 2021 12:39:06 +0100*

## [NOI2013] vector inner product

subject
Portal to LOJ
thinking
This question is really, really, really, really outrageous. Better from
k
=
2
k=2
k=2 start.
First of all, we need to think of such a thing: multiple vectors and multiple vectors, fi ...

Posted by **greip** on *Mon, 27 Dec 2021 01:58:04 +0100*

## [PAT] Spring 2021 PAT Class A problems

1. Arithmetic Progression of Primes (20 points)
In mathematics, an arithmetic progression (AP, equal difference column) is a sequence of numbers such that the difference between the consecutive terms is constant. In 2004, Terence Tao and Ben Green proved that for any positive
n
...

Posted by **ddoc** on *Thu, 16 Dec 2021 19:32:46 +0100*