implementation

问题 An easy question I suppose 回答1: No. iBatis is not an ORM mapper like Hibernate, so it doesn't implement JPA. JPA isn't even mentioned in official user guide. By the way, iBatis is retired. It's been renamed to myBatis, so you should use that instead. 来源： https://stackoverflow.com/questions/4225231/does-mybatis-implement-jpa

问题 SAP announced Blue Ruby, a version of Ruby that runs inside the ABAP Virtual Machine. This seems to lend additional credibility to the Ruby language but, except for SAP developers, does this have any applicability to the rest of the Ruby community? I'm just wondering what other significance this may have. Additional job opportunities, perhaps, for Ruby developers to be hired to work on SAP projects? Any other potential benefits for Ruby programmers? Also, something I'm not clear about:

问题 I have 2 classes Base and Derived (derived publically from Base). When I write - Derived * d1 = new Derived; delete d1; Compiler sees that d1 is a Derived type object. So it calls the derived class constructor (which calls the base class constructor). I have 2 questions here - 1) Why do we follow this order? 2) How do these constructors work together to allocate memory? I need some implementation details Now the next statement is delete d1. So compiler sees that d1 is a derived type object

问题 I have downloaded the latest cocos2d from their site, and I have unzipped it. Now I am confused exactly how to implement it into an already existing project. What files do I drag over and is there anything else I have to do besides that? Thanks! 回答1: You can link cocos2d into your project as shown here. He uses a special version that supports arc, but it works in exactly the same way with the original version. Then in a next step make sure that you import all the important libraries:

问题 I have a tree where every node may have 0 to N children. Use-case is the following query: Given pointers to two nodes: Are these nodes within the same branch of the tree? Examples q(2,7) => true q(5,4) => false By the book (slow) The straight forward implementation would be to store a pointer to the parent and a pointer to a list of children at each node. But this would lead to bad performance because the tree would be fragmented in memory and therefor not cache-aware. Question What would be

问题 I'm in need of some tips regarding a small project I'm doing. My goal is an implementation of a Fast Fourier Transform algorithm (FFT) which can be applied to the pricing of options. First concern: which FFT? There are a lot of different FFT algorithms, the most famous one being Cooley-Tukey. My thoughts on this: I prefer the most simple one, since this is no thesis or big project, just a course on Algorithms. But it has to be compatible with option pricing (in contrast with the most - well

问题 I want to make a FIR filter. I have an array of coefficients (buffer[size]) and an array of data (filter[size_filter]). I have to do a convolution between the two arrays: for(j = 0;j < size+size_filter;j++) { output[j] = 0; for(i = 0;i < size_filter;i++) { output[j] += buffer[i]*filter[j-i]; } } output[size+size_filter] is the result. Where I'm wrong? 回答1: output[j] += filter[i]*buffer[j-i]; and also make sure that j-i will not be negative 回答2: From what I can see, none of the answers given

问题 What is the correct syntax for having function implementation in a separate file? For example: foo.h int Multiply(const int Number); foo.cpp #include "foo.h" int Multiply(const int Number) { return Number * 2; } I see this used a lot, but when I try it I get an error having to do with a missing main() function. I get the error even when I try to compile working code. 回答1: Roughly speaking, you need to have a main() function inside one of your C++ files you are compiling. As the compiler says,

问题 I am reading a file that is filled with hex numbers. I have to identify a particular pattern, say "aaad" (without quotes) from it. Every time I see the pattern, I generate some data to some other file. This would be a very common case in designing programs - parsing and looking for a particular pattern . I have designed it as a Finite State Machine and structured structured it in C using switch-case to change states. This was the first implementation that occured to me. DESIGN: Are there some

问题 I have already seen two stack implementation of this question but I am really confused as how one could get O(1) operation. consider following example: S1[3542761986759] S2[3332221111111] The idea/algorithm here is Push element E on S1 Check to see if top of S2 >= E and if true, insert E on S2 But when getMin is called, we return top of S2 but that leaves S2 in weird state as S2 contains repeated current min elements, so the solution is to search next minimum element in S2 and return it. This