Mathematical knowledge of Sinorgchem in the first round of noip preliminary csp-j1 csp-s1 (I)

near 15 10000 contestants NOIP 2018 Preliminaries , The scale of the competition hit another record high

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about 15 10000 contestants NOIP2018 Preliminaries , The scale of the competition hit another record high ！_ The rematch

CCF NOIP2018 Improve the score line of the first prize of the group

https://jingyan.baidu.com/article/e52e36150a783740c60c519a.html

At home noip The number of participants is growing rapidly

Sina blog

Preliminaries _ Summary of wrong math problems

Preliminaries _ Summary of wrong math problems - logiccc - Blog Garden

take 5 Sequence of numbers , Whatever the original order , At least several comparisons can be made , Finish sorting from small to large .

take 5 Sequence of numbers , Whatever the original order , At least several comparisons can be made , Finish sorting from small to large ._ Baidu knows

Sina blog

noip The subject of 、10． take 5 Sequence of numbers , Whatever the original order , At least they can pass （ ） Compare it to , Finish sorting from small to large .A. 6 B. 7 C. 8 D. 9 E. 101． take 2006 Individuals are divided into disjoint subsets , Each subset has at least 3 personal ,_ Homework help

On the exchange times of array sorting

On the exchange times of array sorting _liuzibujian The blog of -CSDN Blog _ Select the number of sorting exchanges

A summary of the second kind of Stirling numbers

A summary of the second kind of Stirling numbers - Deadecho - Blog Garden

Solve a programming problem .

（ subset division ） take n Number （1,2,…,n） Divide into r A subset of . Each number happens to belong to a subset , Any two different subsets have no common number , also

There is no empty set . Record the total number of different division methods as S(n,r). for example ,S(4,2)=7, this 7 The three different methods of division are {(1),(234)},{(2),(134)},

{(3),(124)},{(4),(123)},{(12),(34)},{(13),(24)},{(14),(23)}. When n=6,r=3 when ,S(6,3)=______________.

（ Tips ： Fix a number first , For the rest 5 Consider the number of S(5,3) And S(5,2), The original fixed number is analyzed in these two cases .）

Solve a programming problem .（ subset division ） take n Number （1,2,…,n） Divide into r A subset of . Each number happens to belong to a subset , Any two different subsets have no common number , There is no empty set . Record the total number of different division methods as S(n,r). for example ,S(4,2)=7, this 7 Kind of no _ Homework help

 

The shortest route （ Permutation and combination ） Their thinking

The shortest route （ Permutation and combination ） The streets of a city are a very regular rectangular grid Yes 7 A north-south longitudinal sister 5 An east-west street Now it's going to hit the southwest corner A Go to the northeast corner B How many kinds of shortest routes are there ?_ Homework help

（ The shortest route ） A city The street is a very regular rectangular grid （ See the picture below ）, Yes 7 A north-south longitudinal street ,5 Tiaodong The westward cross street . Now we need to start from the southwest corner A Go to the northeast corner B, How many are the shortest ways to walk ?_________________ namely （4 That's ok 6 Column rectangle _ Homework help

Fourteen noip Preliminary questions It is related to the minimum exchange times of sorting

Fourteen noip Preliminary questions With respect to the minimum number of exchanges of the sort, the array {8,23,4,16,77,-5,53,100} The elements in the are sorted from large to small , You can swap any two elements at a time , At least exchange （ ） Time ._ Homework help

【 Solve with your toes NOIP】(1):NOIP2010~NOIP2015 Popularize group problem solving

【 Solve with your toes NOIP】(1):NOIP2010~NOIP2015 Popularize group problem solving _xiaoyao24256 The blog of -CSDN Blog

2014NOIP Preliminary competition of popularization group Two 、 problem solving 1、 hold M The same ball

Sina blog

【NOIP】 Popularization group 2014 problem solving

【NOIP】 Popularization group 2014 problem solving _vmret The blog of -CSDN Blog

Permutation and combination "n Put a ball in m Boxes m" problem summary

Permutation and combination "n Put a ball in m Boxes m" problem summary _ Xiaoyao, Qi's blog -CSDN Blog _n Put a ball in m A box theorem

Discrete Mathematics ：n The same ball , You can put m In the same box , Empty boxes are allowed , Ask how many different ways _zb_tjw The blog of -CSDN Blog _ Put the same ball into the same box

2015NOIP Preliminary competition of popularization group Two 、 problem solving 1. Rearrange 1234 So that every number is not

Sina blog

stay 1 and 2015 Between ( Include 1 and 2015 , ） Can not be 4.5.6 How many of the three numbers are arbitrarily divided by one number ？？

stay 1 and 2015 Between ( Include 1 and 2015 , ） Can not be 4.5.6 How many of the three numbers are arbitrarily divided by one number ？？_ Baidu knows

stay 1~2015 Between ( Include 1 and 2015) Can not be 4,5,6 How many numbers are divided by any number between them _ Baidu knows

noip2015 Promotion group topic explanation

noip2015 Promotion group topic explanation

NOIP 2016 Preliminary popularity group C/C++ Detailed answers

NOIP 2016 Preliminary popularity group C/C++ Detailed answers - Simple books

NOIP 2016 Preliminary popularity group C/C++ Detailed answers _ Haitian Yishu's blog -CSDN Blog

1. One 1×8 The square pattern of （ Do not rotate ） Use black 、 Fill each square with two colors of white ..55 answer

1. One 1×8 The square pattern of （ Do not rotate ） Use black 、 Fill each square with two colors of white ..55 answer _ Baidu knows

NOIP 2017 Preliminary popularity group C/C++ Detailed answers

NOIP 2017 Preliminary popularity group C/C++ Detailed answers _ Haitian Yishu's blog -CSDN Blog

NOIP2017 Preliminaries Walk around the origin

NOIP2017 Preliminaries Walk around the origin - Shizi holds Yu Yu - Blog Garden

if f[0]=0,f[1]=1,f[n+1]=(f[n]+f[n-1])/2, With i The increase of ,f[i] Will be close to ?

if f[0]=0,f[1]=1,f[n+1]=(f[n]+f[n-1])/2, With i The increase of ,f[i] Will be close to ?_ Baidu knows

noip2017 Preliminary summary

noip2017 Preliminary summary _wanherun The blog of -CSDN Blog

2018NOIP Analysis of the first round of the popularization group

2018NOIP Analysis of the first round of the popularization group _QuantAsk The blog of -CSDN Blog _noip2018 Analysis of the questions in the preliminary round of the popularization group

Less than 1000 And with the 1000 What is the sum of all natural numbers of Coprime

Less than 1000 And with the 1000 What is the sum of all natural numbers of Coprime _ Baidu knows

The length is 1 The line segment , Randomly select two points on it , Divide the line segment into three segments , Ask this 3 Fields can form a What is the probability of a triangle

The length is 1 The line segment , Randomly select two points on it , Divide the line segment into three segments , Ask this 3 Fields can form a What is the probability of a triangle _yingsun The blog of -CSDN Blog _ The length is 1 Random selection on the line segment of 2 A little bit

from 10 The set of elements consists of ______ A subset of ．

from 10 The set of elements consists of ______ A subset of ． _ Homework help

Set containing 10 The number of all subsets of the set of elements is S, Among them is by 3 The number of subsets composed of elements is T, be T/S The value of is ______

Set containing 10 The number of all subsets of the set of elements is S, Among them is by 3 The number of subsets composed of elements is T, be TS The value of is ______．- High school math -n Multiple questions

Given n Number , In the worst case, use ╔ 3n/2－2 ╕ Compare and find out this n The maximum and minimum values of elements in the number

Given n Number , In the worst case, use ╔ 3n/2－2 ╕ Compare and find out this n The maximum and minimum values of elements in the number Input Contains multiple sets of test data . The first element of each set of test data is the number of integers n, Next is n It's an integer .0 End of the said . n_ Homework help

The number of spanning trees of undirected connected graphs

The number of spanning trees of undirected connected graphs - saltless - Blog Garden

NOIP The questions and answers of the preliminary round of the popularization group over the years （ Solve the problem ）

http://www.shaoerbianchengwang.com/1691.html

001_ The simulated test questions of the preliminary round of the popularization group （ video ）

001_ Popular group questions _ Bili, Bili _bilibili

NOIP You must not lose points on these questions in the preliminary contest ！

NOIP You must not lose points on these questions in the preliminary contest ！

noip2014 The seventh lesson on the analysis of the test questions of the preliminary improvement group

https://v.youku.com/v_show/id_XODM4NTM4MjQ4.html

NOIP2018 Preliminaries Problem solving report （C++ Universal ）

NOIP2018 Preliminaries Problem solving report （C++ Universal ） - yzx_1798106406 - Blog Garden

【 The latest news 】NOIP2018 The real questions and answers of the preliminary popularization group and the improvement group will be released ！

Prepare for war NOIP2018_ Choose your own true question

Prepare for war NOIP2018_ Choose your own true question _ Yunke Sanren's blog -CSDN Blog