Since you've already included string, why not use std::string for all your strings rather than messing about with char arrays, with their fixed length, no overflow protection, do it yourself alloc and free problems etc etc.
> char temp[65535 - length + 1]; C++ doesn't have variable length arrays, you're relying on a compiler-specific extension to do this. static char temp[65535]; would be a quick fix hack in this particular case.
The first step would be to create a program which allows you to input a team / player, and print the information back to the user. Until that works, there is no point trying anything else.
NAME
ftw, nftw - file tree walk
SYNOPSIS
#include <ftw.h>
int ftw(const char *dir, int (*fn)(const char *file, const struct stat *sb, int
flag), int nopenfd);
> The reason for this error might be that I am not allocating any memory for the pointer(correct me if I am wrong). Yes, it has been allocated, but the memory which you're pointing at is read-only (meaning you can't change it). The variable p can be changed (say p="world"), but what it points at cannot be changed (you get the error).
> 1) Will the compiler places the string "name" in the stack segment of the memory No, only p is on the stack, the string is somewhere else, allocated by the compiler. In effect, the compiler does this for you. You just never see (or know) the name of the array it creates.
Both your pointer and string are on the stack, and you can change the string via your pointer.
> 2) Will the string "name" be in the stack??? No, see above.
> 3) If that is the case why I am getting the error at the run time. The memory is anyhow allocated to the string. Because the 'anon' string itself is not WRITEABLE. Yes, it is allocated, no you can't change it.
Basically, you look at the first element of each input list, and decide which one you want first. You then remove that from the head of whichever input list and append it to your result list. Keep doing that until both input lists are empty.
> char *url; > url = sUrl.c_str(); Which got you error C2440: '=' : cannot convert from 'const char *' to 'char *' Understand that the c_str() method returns a const pointer for a reason, and that's to try and stop you from sneaking in the back door to change the string.
> char *url; > strcpy(url, sUrl.c_str()); Which got you warning C4700: local variable 'url' used without having been initialized Yes, you used a variable before you initialised it. Expect string data to be sprayed all over some unknown memory.
You can either allocate it as Lerner suggests, Or simply have const char *url; to satisfy the const requirements.
Or just do what GloriousEremite showed, and scrap the whole temporary used once thing.
> while(charbuff!=' ') Maybe this is false on the first iteration, therefore i never gets modified and the function exits without doing anything.
> ........... some code Post COMPLETE whole programs which show the problem. Most efforts to snip out "irrelevant" code usually end up snipping out something really vital to the question at hand. This seems to be no exception.
> can anyone explain me why the values are not swapped in the below code ?? Another problem is that your pointers are uninitialised - who knows, maybe they both point at the same memory location.
#include <stdio.h>
int swap ( int *a, int *b ) {
*a ^= *b;
*b ^= *a;
*a ^= *b;
}
int main(void)
{
int a = 2, b = 3;
printf( "%d %d\n", a, b );
swap( &a, &b );
printf( "%d %d\n", a, b );
swap( &a, &a ); /* swap with itself */
printf( "%d %d\n", a, b );
return 0;
}
What do you get with the final line of output? Is it what you expected?
1. Defined - every compiler does the same thing. Eg. that && and || are short-circuited.
2. Implementation defined - compilers must document what they do Eg. what right-shift >> does on signed negative integers. Some implementations shift in zero, others shift in the sign bit. Both are correct, yet can cause problems for your code.
3. Unspecified - like implementation-defined, but undocumented. Eg. the order of evaluation of sub-expressions.
4. Undefined - absolutely anything can happen. You may get the answer you expect, you may get an unexplainable answer, you may get a crash in your program. You may even get a crash (or worse) in your OS. There is no point in even trying to understand what your compiler does, because whatever it does, it doesn't have to be consistent about it. And everyone elses compiler is going to be different anyway.
Code which relies only on case 1 is good code. Case 2 is OK, so long as it's well documented, but it would be much better avoided if at all possible. Code which relies on 3 or 4 is on very shaky ground, and is best avoided.
> it said pointer was best way to access dynamic arrays. It's the only way.
But both variables have the same type.
car * catalogue = new car[c];
car *ptr = &catalogue[0];
All you've actually achieved is changing a 9-letter variable name (with some meaning) for a 3-letter variable name (with very little meaning). ptr[n] and catalogue[n] do exactly the same thing.
What you've also created is a dangling pointer problem. By having two variables pointing at the same memory you introduce the possibility of accessing ptr[n] long after you've done delete [ ] catalogue.
> car *ptr = &catalogue[0]; What does this achieve?
You can do this cin.getline(catalogue[i].make,20); > delete [] catalogue; You need to do this after you've finished printing the data, not before.
> however on the first run through the loop, the "make" of the car is not stored in the array Maybe you typed a space after the input of how many cars So the get() only got rid of the space, not the newline which would immediately satisfy the getline.
> array[i+1] *= array[i] ; Since this is just short for array[i+1] = array[i+1] * array[i] ; All the calculations involve undefined values because i+1 element is read before being written (in the absense of any other initialisation).
Start by stating what the problem is you're trying to solve rather than imagining using strstream is the answer. Tell us the problem you're trying to solve, not how to fix your solution.
Have you considered for example a vector of unsigned chars for storing your binary data?
> but the problem is that I can't access the streambuf "bp member" of my strstream. The whole point of C++ is that internal representation is guarded by the class interface. If you're always smashing away the interface to get to the internals then you're really doing something wrong.
> but there's specific reasons why I was wanting to compile and run under Miracle C. Because you're a masochist? Like Dave said, Miracle C is a silly PoS compiler which looks great if your homework was "write a C compiler", but is utterly useless for anything more complicated than "hello world". Even crusty old TurboC had more features, and dev-c++ just wipes the floor with it. The bonus round is that dev-c++ is really $0 whereas Miracle C is $$$ nagware. Perhaps the real miracle is that people actually pay for that junk.
The only thing you will learn is frustration, and there's plenty of that coming your way even with a decent compiler.
If it's your school telling you to use that crud, then find a better school because they'll be incapable of teaching you anything useful.
> i finish writing my code but i have no idea how to write the pseudocode since classes and functions are involved You're supposed to do the design (classes etc) and pseudo-code before doing the actual code.
They're the design and scaffolding you use to build the thing you really want.
> I thought the memory would be given back to the memory manager for general use. That's what I said - it goes back to the memory manager within the program to be used in further allocation requests your program may make.
It's all virtual memory anyway, if your program stops using blocks of memory for a while, then the OS will likely swap that memory out to disk.
> char temp[81]=""; But apparently your words are up to 1000 characters long. Fix this, or fix your arrays.
> y[1000][1000] 1MB of unused space, just get rid of it.
It seems to me that you're likely to be blowing away your entire stack (and much more) before you've even begun. Start with a small file of only say 10 short strings and verify that your algorithm works. Then scale it up to full size. Try it with a file of only TWO words, and step through the code with a debugger.
> if (strcmp(a[d],a[lower])<=0) Try using the x array (the one you read into) rather than something completely useless liike your a array.
> but the memory that was used is not freed up If you worked this out by watching task monitor or process explorer, then it wouldn't. The program memory manager usually holds onto the memory for future memory requests from your program (which is relatively quick), rather than asking the OS each time (which can be rather slow).
> It waits only process number 1, and not number 2. Why? Because you asked it to.
If you use -1 as the pid, then it will wait for any child, and return with the pid of the child which ended. Put that into a loop until all your children have ended, then carry on as normal.
> Elapse Time Since Program Start Working What do you mean?
The amount of time, as measured by the clock on the wall?
The amount of time the program has used? If your program is low priority, say it's only using 10% of the CPU, there is a big difference between "user" time and "program" time.
> Board(GridDimension,GridDimension,Empty),//This line causes this error So use Board.push_back(GridDimension); // etc within the body of the constructor instead?
