Calculus blockchain code

1.

blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. Blockchain is an important concept of bitcoin,

in essence, it is a decentralized database. At the same time, as the underlying technology of bitcoin, it is a series of data blocks generated by using cryptographic methods. Each data block contains a batch of information of bitcoin network transactions, Used to verify the validity of its information (anti-counterfeiting) and generate the next block

extended data

most blockchain public chains are limited by scalability. The biggest feature of blockchain technology is decentralization, which requires that all accounts in the network need to deal with the accounting process. Distributed accounting has high security, low misoperation rate, political neutrality and correctness

however, blockchain technology embraces these features at the same time, sacrificing scalability, unable to meet the personalized supervision, and slightly insufficient in protecting data privacy. Moreover, with the increase of the number of ledger, the interaction delay will increase exponentially, that is to say, the more ledger in the blockchain network, the higher the delay

2. This should be a problem in two aspects: open source code refers to what we all know about this piece of code; As for the modification and destruction of the system, it should be the problem of system protection, so that people who want to modify and destroy can not enter. For example, there is a very valuable cultural relic in the glass window of a museum, which is on public exhibition. If you ask this question, someone will destroy or steal it.

3. Blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. The so-called consensus mechanism is a mathematical algorithm for building trust and acquiring rights and interests between different nodes in the blockchain system.

blockchain is an important concept of bitcoin, which is essentially a decentralized database and serves as the underlying technology of bitcoin. Blockchain is a series of data blocks generated by cryptography. Each data block contains the information of a bitcoin network transaction, which is used to verify the validity of the information (anti-counterfeiting) and generate the next block

in a narrow sense, blockchain is a kind of chained data structure that combines data blocks in chronological order in a sequential way, and it can not be tampered with and forged by cryptography

broadly speaking, blockchain technology uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, and uses cryptography to ensure the security of data transmission and access A new distributed infrastructure and computing method for programming and operating data by using intelligent contract composed of automated script code
go language + blockchain training course:
1 What are the advantages of go
advantages of go
1: performance
2: language performance is very important
3: developer efficiency & don't be too innovative
4: concurrency & Channel
5: fast compile time
6: team building ability
7: powerful ecosystem
8: gofmt, Mandatory code format
9: grpc and protocol buffers
can be directly compiled into machine code, independent of other libraries. Glibc version has certain requirements, and deployment is completed by throwing a file
static type language has the feeling of dynamic language. Static type language can check out most hidden problems when compiling, while dynamic language has the feeling that there are many packages that can be used and the efficiency of writing is very high.

4. Go language + blockchain training course:
from the characteristics of the language itself, go is a very efficient language, which highly supports concurrency. Go language itself pays more attention to distributed systems, and concurrency processing is relatively good, such as advertising and search, which are high concurrency servers
go language advantages:
excellent performance, can be directly compiled into machine code, does not rely on other libraries, go is extremely fast. Its performance is similar to Java or C + +
concurrency is supported at the language level, which is the biggest feature of go. It is born to support concurrency, and go is the concurrency supported in gene, which can make full use of multi-core and make it easy to use concurrency
the built-in runtime supports garbage collection, which is one of the features of dynamic language. Although GC is not perfect at present, it is enough to cope with most of the situations we can encounter, especially GC after go1.1
it's easy to learn. The authors of go language all have the gene of C, so go naturally has the gene of C. There are 25 go keywords, but the expressive ability is very strong. It almost supports most of the features you've seen in other languages: inheritance, overloading, object, etc
rich standard libraries, go has built a large number of libraries, especially the network library, which is also my favorite part< As like as two peas, br / > built-in powerful tools, Go language is built with many tools chain, the best should be gofmt tools, automatic formatting code, make team review become so simple, code format is exactly the same, it is very difficult to think differently.
cross platform compilation and fast compilation. Compared with the sluggish compilation speed of Java and C + +, the fast compilation time of go is a major efficiency advantage
disadvantages of go language:
package management: package management of go language is absolutely not perfect. By default, it has no way to make a specific version of the dependency library, nor can it create replicable builds. In contrast, python, node and Ruby all have better package management systems. However, with the right tools, the package management of go language can also perform well
lack of development framework: go language does not have a major framework, such as Ruby's rails framework, Python's Django framework or PHP's laravel. This is a heated discussion in the go language community, because many people think that we should not start with using frameworks. This is true in many cases, but if you just want to build a simple crud API, it's much easier to use Django / djrf, rails laravel, or Phoenix
exception handling: go language can help developers deal with compilation errors by simply returning errors (or call stack) through functions and expected calling codes. Although this method is effective, it is easy to lose the scope of the error, so it is difficult to provide meaningful error information to users. Error package can solve this problem by allowing us to add context and stack trace to return error
another problem is that we may forget to handle errors. Static analysis tools such as errcheck and megacheck can avoid these errors. Although these solutions are very effective, they may not be the right way.

5. Many shopping malls will have a point mechanism, and it has become a very common marketing way for consumers to send points. The application of blockchain is derived from the integral system. Through the integral system of blockchain, we can 1. Build the credit enhancement process of integral issuance, which lays the foundation for circulation; 2. The margin cashed by the blockchain integral bank is the exchange endorsement; 3. From service-oriented to user-oriented, users can transfer and exchange independently, blockchain is responsible for matching, and points play a role in market decision
4; 5. Ecological incentive mechanism is introced. At present, the domestic blockchain integration system technology development has the strength of micro three cloud technology developers.

6. http://..com/question/425395358.html
excel中vba数值积分代码
Sub 求定积分()
On Error Resume Next
Dim N1 As Integer, N As Integer, i As Integer
Dim S As String
Dim C1 As Double, C2 As Double, C3 As Double
If ActiveSheet.UsedRange.Rows.Count < 2 Then
Cells(1, 1) = "积分式"
Cells(1, 2) = "下限"
Cells(1, 3) = "上限"
Cells(1, 4) = "计算结果"
S = MsgBox("请从第二行开始，每一行可计算一个积分" & Chr(13) & "第一列输入积分式，积分变量只能用X，" & Chr(13) & "并且要按照Excel公式的标准输入", , "提示信息")
End If
N = ActiveSheet.UsedRange.Rows.Count
Columns(5).Hidden = True
For N1 = 2 To ActiveSheet.UsedRange.Rows.Count
S = Cells(N1, 1)
C1 = Cells(N1, 2) '积分下限
C2 = Cells(N1, 3) '积分上限
If S = "" Or C1 = 0 And C2 = 0 Then GoTo w1
S = UCase(S)
N = InStr(S, "X")
Do While N > 0
S = Left(S, N) & " " & Mid(S, N + 1)
Mid(S, N) = "e2"
N = InStr(S, "X")
Loop
Cells(N1, 4) = "=" & S
N = 2000 '小于32767,N值越大,结果越精确
C3 = (C2 - C1) / N
Cells(N1, 5) = C1
C2 = Cells(N1, 4) / 2
For i = 1 To N
Cells(N1, 5) = i * C3 + C1
C2 = C2 + Cells(N1, 4)
Next i
Cells(N1, 4) = (C2 - Cells(N1, 4) / 2) * C3
w1: Beep
Next N1
End Sub

7. It's rare for a teacher to write a program in any language. I think you can directly download the help documents of the development tools for the calculus formula and trapezoidal formula of the calculator. Those who are sure that someone else has already made a math class method for the programmer to call directly, you just need to find out the method and open its source code, This must be a compressed package, because you are using VB, so I don't know what the help document of VB development tools is, because I always use java to write programs, and occasionally use C + +, but VB does a good graphical interface

8. Unknown_Error

#include<stdio.h>
#include<math.h>
doubleinteg(doublesub,doublesup,doublef(double));
doublef(doublex);
intmain(void)
{
	printf("%E
",integ(5,7,f));
	return0;
}
doubleinteg(doublesub,doublesup,doublef(double))
{
	doublei,sum=0;
	for(i=sub;i<=sup;i+=1e-6)
	{
		sum+=f(i)*1e-6;
	}
	returnsum;
}
doublef(doublex)
{
	returnexp(5*x)*pow(x,4)-3*x;
}

10. This thing is not finished in two sentences. You'd better learn a book about numerical calculation methods. Otherwise, it's impossible to teach you through a few sentences unless someone else writes for you