565 Posted Topics
 | A multitude of errors, mostly caused by trying to write everything in on go. (a) Patient includes an instance to Doctor. Therefore you must have a declaration of Doctor before Patient is declared. If it was just a reference or pointer you could have used a forward declaration e.g [icode] … |
| | You problem is scope. Let me walk through it even if you are familiar with it. (a) If you want to use m in class X. All is ok. (b) If you want to use m in class Y. Again all is ok, assuming Y does not define a local … |
| | Using gcc, [icode]#include <string.h>[/icode], provides a back-compatability system for stuff like [icode]using std::memcpy;[/icode] etc... You include that when you are using code that does not use the std::strcpy form but you want to just write [ICODE]strcpy(...)[/ICODE]. Since you almost never want [ICODE]using namespace std; [/ICODE]it is a nice half-way house, … |
| | I think that you are after the distance algorithm e.g. [code=c++] std::vector<int> A; // ... stuff here vector<int>::iterator i = find(A.begin(), A.end(), 9); // can use std::vector<int>::difference_type // or static_cast to int etc. long int index=std::distance(v.begin(),i); [/code] Note it work with std::list and other containers with a reversible iterator. The … |
 | I normally think it is better to wrap these kind of fabs() type test in a testing namespace , that provides a template form like this [code=c++] namespace Approximate { template<typename T> bool equal(const T& A, const T& B,const double precision = 1e-4); template<typename T> bool notEqual(const T& A,const T& … |
| | Depending on the problem use a template parameter. But the trick is to use a common base class. Imagen this: [code=c++] class pixelBase { // ... Stuff ... virtual void setPixel(); }; template<int pixelType> class pixelItem : public pixelBase { virtual void setPixel(...); }; [/code] This doesn't always give you … |
| | If you are writing a Pong game, I think that you are going to learn a lot, so well done. Second AI in Pong is interesting, there are at least three models: (a) pure deterministic. That is the computer calculates exactly where is wants to be and tries to go … |
| | Your zero's + poles are correct, your LCCD is incorrect as you have missed a term. |
| | This code is NOT fine. The problem is the there is not a copy constructor or an assignment operator. The requirement for using vectors SAFELY is that they work. If you do not provide them, then the compiler uses a default version. Your class requires that you has std::string which … |
| | Well types like int, float etc are fundermental, i.e. they are not classes. How the are converted into machine code requires examination of the compiler source code. Types like ostream and string are part of the standard lib. So they are classes. This means that you can look at the …  |
| | Well the basic FFTs are available in the GSL (gnu-scientific lib.) [URL="http://www.gnu.org/software/gsl/manual/html_node/Fast-Fourier-Transforms.html"]http://www.gnu.org/software/gsl/manual/html_node/Fast-Fourier-Transforms.html[/URL] If you are doing polynominals, you are very likely to need the complex form, and depending on exactly how you set it up the 2D form of that. However, you should also look at FFTW3 [URL="http://www.fftw.org/"]http://www.fftw.org/[/URL] which is … |
| | Several things from your question: First the string part. You have many options (a) you can indeed use insert but the method requires an iterator to define the position for insertion. (b) the easiest to use simply += e.g [code=c++] char p='x'; std::string A("test"); A+=x; // A is now testx … |
| | First off, I agree that you should compile often. Second: The main point, there are FAR too many fixed numbers. e.g. [icode]"Round trip from Tokyo to Florida,America 2500$ per"[/icode] That is horrific. Put [code] const double TokyoFloridaCost(2500); const double YenDollarExchangeRate(14.3); [/code] at the top of the code and use the … |
| | Quadratic multilication: If you multiply two quadratics together you don't normally get another quadratic, (normally it is a quartic ([tex]x^4[/tex]) ). What that really means is that quadratic(ness) should a property of a class, not itself a class. [Assuming that you are going to require multiplication] So write a polynominal …  |
| | You can do this in a number of different ways. What you seem to have here is two processes to do, which have different efficient in different containers. That means that you have to have a compremise. So, let use construct a simple consideration with the basic items: You can … |
| | At a guess. I think that your problem is that you are using long, by itself, and not long int or long unsigned int , or long double etc. Yes there is a fall back of long to long int, but does that still apply to long* and going to … |
| | while you are fixing this. Please note that you often write [code=c++] for (int count=0;count<customer;count++); { // Stuff } [/code] Observe the semi colon after the for loop that should not be there since the body is not going to get executed until after the pointless loop. gcc gives warnings … |
| | Re: Weird cast error This is C++ not C, so I would have written: [code=c++] b= -1*static_cast<int>(x)/2; [/code] The main advantage of this is the you have an explicit bracket around the section you are casting and it is a BIG flag that you are changing type. Something that in numerical code is often …  |
| | Well the problem seems to be that you expect the array to be terminated with a 0 . This is a mess. What I think you have done is confuse the normal mechanism for strings e.g. [code=c++] char* X="Fred"; // This gives // X[0]=='F' ... X[3]=='d' X[4]==0 [/code] with any … |
| | With that kind of error message I would be expecting that you have over or under run the array indexes. If you post some more code, we can have a look. But check that you don't let your indexes get to 400 or something. (or negative!). |
| | This thread is getting a bit messy. So I am going to write a quick summary and how I would tackle the problem. First: Coordinates are almost never integers, and once you have solved a 2d problem you often need a 3d solution, and sometimes higher dimensions. What has been … |
| | > What is wrong with my sorting function? I am trying to put numbers in ascending numbers. Nothing, in the fact that it actually works, BUT it is a bubble sort and hence very inefficient. If you are still having problems check your calling routine, are you using an array … |
| | Ok it is a singleton, so there are several methods, but teh stuff above doesn't look 100% ok. First : if you are going to use a singleton you want to be 100% certain that there are no repeats. That means that if you want to use the static pointer …  |
 | First of all, Narue's explaination is really well done (as usual). Second, has ClockOwl noticed that REGARDLESS of the template issue he has written the algorithm wrong and you get absolutely no items in x after kill_dupes is called you might as well write [code=c++] template<typename T> void kill_dupes(vector<T>& X) …  |
| | Sorry, but most of these solutions are inelegant and that is because to achieve randomness they require an excessive number of random number calls: (a) Shuffling the stack by selecting two cards and exchanging requires about 7 times the deck of length to get to nearly random on a 52 …  |
| | First : As pointed out there are vectors of vectors. That is ok. But often you want a 2d array, i.e each column is the same length. So try the boost::multi_array. Lots better. Second : you can do what you want with pointers/new/delete etc BUT you have to get it … |
 | Looks to me that you are not creating an instant of the template class for `<int>`. You have put the link body in a .cpp file. That is perfectly acceptable and good practice if the body is large. BUT you have not created an explicit instance of it. So add … |
| | You have several potentual problems : (a) If you have an extra character at the end of the file (e.g. '\n') Since you test fin.eof ONLY at the start of each sequence you probably read the array then find that you are not at the end of the file , … |
| | Ok: Not perfect but a good attempt: First off scoping rules: if you have a class variable e.g. [code=c++] class A { int index; }; [/code] Then that variable is effectively hidden by this [code=c++] class A { int Index; void run(int Index) const { Index+=20; } }; [/code] Note … |
| | However, you can use the std::distance function to determine the distance between two sequentual iterators. e.g. [code=c++] std::vector<int> A; std::list<int> B; // ... populate A,B: std::vector<int>::iterator AIter=find(A.begin(),A.end(),7); std::list<int>::iterator BIter=find(B.begin(),B.end(),7); std::cout<<"Distance Vector == "<<distance(A.begin(),AIter)<<std::endl; std::cout<<"Distance List== "<<distance(B.begin(),BIter)<<std::endl; // THIS DOES NOT WORK:: // std::cout<<BIter-B.begin() <<std::endl; [/code] The list iterator is not … |
| | First off rayone is just random troll. Second: Your problem is that you have (a) forgotten to put a endl after the output and (b) forgotten that x and y are separate entities. So you need [code=c++] cout<<x<<y<<endl; [/code] finally you forgot that after an if you need { }, … |
| | The list you are after in in [URL="http://gcc.gnu.org/gcc-4.3/cxx0x_status.html"]http://gcc.gnu.org/gcc-4.3/cxx0x_status.html[/URL] I am assuming that you are using 4.3. However, I am sligthly mystified , I though that you can only write what you have if you are using static or const. If you have the C++0x reference could you/someone post it please. … |
| | Re: c++ routine And your problem with this assignment is..... Suggested reading: [URL="http://www.daniweb.com/forums/announcement8-2.html"]http://www.daniweb.com/forums/announcement8-2.html[/URL] |
| | Sorry but anubis' process injection code, is normally used to put code into running windows processes for the purpose of running a rootkit. As far as I can tell. So why should we help given the site rules and likely purpose. The only good news is you don't seem to … |
| | Well depite the fact that this looks awful, you almost definately have a memory leak. You initialize line to fslen+10, whatever fslen is. Then you do not delete it. However, as vmanes says, you are not giving us much to go on. I would, at the minimum post the class … |
| | If you are using that much memory, you will be much better off using the boost array/multi_array classes. Then you will be better off using Blitz. Word of warning: write the code using boost/stl untill it works with smaller data sets. THEN use Blitz. Otherwize the error messages and other … |
| | Re: C++ problem It still amuses me to see stuff like: [quote](after any other discount is subtracted).[/quote] It doesn't matter what order you apply you % discounts. However, rather than that : this is c++ the advantage that gives you (along with many other languages) is you can code stuff as functions or … |
| | Answer is: Start again You have [code=c++] while (getline(cin, info) && info != "") { if ( isInVec(word[info.length()], info) == false) word[info.length()].push_back(info); } [/code] Now word starts empty, so IMMEDIATELY, you access work[X] were X is a large number. Then you push back to that place. That is memory corruption. … |
 | You can't copy it to a set and back again without breaking the order. Sets store on a compiler defined manor but normally red-black trees. Hence you will destroy the order. The easiest way is to copy to another vector sort, unique and then find the copies. Another slightly more … |
| | In addition, replace the semi colon on line 21 with a colon ( : ). Swap line 22 with line 23. That will avoid a compiler warning. |
| | First off: The polynominal class, it is a start but you have a number of things to adjust. First off polynominals have three common types of coefficient: complex , floating point (double etc) or polynomial. Note the last one: if you want to express [TEX]3y^2+xy+x^2+1 =0[/TEX] then you will want … |
| | Nucleon is 100% correct that it gives "multiple definition of void Output<unsigned int>" on standard compliant compilers. The standard says that if you put implimentations in a declaration then ALL used specializations must be availiable at that instance. Some compilers do help you out here BUT it is not standard … |
| | Ok you have made several little errors/annoyances and one misunderstanding as I see it. (a) First you [ICODE]#ifndef TEMPLATED_FOO_H[/ICODE] does not finish (b) You use a chained #include system. Please don't, it can be done but write .h file for the classes adn use #include's in the cxx. That will … |
| | Yes certainly you can do that but you have to resolve the instance at some point. So perhaps you want it is another templated class. [code=c++] template<class First, class Second> struct foo { First f; Second s; }; template<typename A,typename B> struct Other { std::vector< foo< A, B > > … |
| | You don't seem to have posted enough code for anyone to tell but are you using: [icode]m_pEcoAreaTeam = new EcoAreaTeam();[/icode] and then the class does not have m_pEcoAreaTeam and you have a scope issue?? If the class has m_pEcoAreaTeam check the spelling. And why the use a global m_pEcoAreaTeam or … |
| | Ok there is no way for us to know the problem but you most likely have a macro [icode]#define size ....[/icode] somewhere in the mess of headers. Have you stripped this down to the minimum- does it still work. If you put a line [icode]#undef size[/icode] just above the [ICODE]PQueue::PQueue[/ICODE] … |
| | Note: [Ark -- I know you know this] but I think it is worth pointing out. If you think that you HAVE to put the template stuff in a single .h file this is wrong. It is ok and works but really really quickly leads to serious slow down on … |
| | First off, well done for using code tags for your first post. Second, your error is that you are returning 0 but actually need to return a string. Try as the last two lines of padBlanks, this: [code=c++] blank+=string1; return blank; [/code] |
| | Syntax mainly: Constructors use variable initializers and an additional code block which happens after initialization. i.e. [code=c++] Customer() : id(0),name("X") { // code block here } [/code] the second version is wrong because you have an extra (). (write long int please!). The only other thing you are going to … |
| | Before I tell you what I think is wrong I am going to tell you what I think has lead you to not being able to solve this. **First:** the layout. It is a mess. Code has to be tidy. I understand you are most likely not a CS grad … |
The End.