There are some tricks to reduce build time 1. Use ninja build system 2. Use lld or mold linkers instead of the standard ld

> also please share the forum post url. What do you mean?

There are some tricks to reduce build time 1. Use ninja build system 2. Use lld or mold linkers instead of the standard ld

Cool I'd still share your problem with other folks on forum and the actual solution to it if you find one It'd useful for others

Hi I’ve got an issue

Bu when I cin it doesn’t

Wish I could send a pic here for a detailed explanation

Well a lot of companies use open addressing hashtables because they are more cache efficient

How can I implemented my C++ knowledge. i wanna do some Real world project so that I can extend my Confidence... can anyone helps me for guidance

yeah, I was looking at clickhouse implementation of hash table in which it has comments saying that any modern hash map use open addressing. It is quite hard for me to understand tho, looking forward to a tutorial

Open Addressing is used. But you are asking for linear probing which is seldom used. Like I mentioned in my previous post, linear probing results in clustering around specific points which is why it is avoided. It doesn't distribute the values around. Other probing methods like Double Hash and Triple hash avoid this problem which is why they are often used. Quadratic probing may also be used.

Linear probing is actually used by most of those large hashtables, but with a catch: to reduce clustering, you need to sacrifice a byte of the hash to transcribe an offset in a table of offsets that evolve following an exponential curve. This limits clustering massively and is configurable to improve it's performance depending on the task

Double hash and triple hash are... very bad when performance is needed

Linear probing is actually used by most of those large hashtables, but with a catch: to reduce clustering, you need to sacrifice a byte of the hash to transcribe an offset in a table of offsets that evolve following an exponential curve. This limits clustering massively and is configurable to improve it's performance depending on the task

Hashing is typically a fast operation. You are not looking at cryptographically secure hash algorithms to probe a free spot in the hashmap anyway for them to be slow. I don't understand why that would slow down performance so much. Can you please clarify that?

I understand what you are suggesting here. This would indeed distribute them but can I see an implementation that does this if you know of any

I understand what you are suggesting here. This would indeed distribute them but can I see an implementation that does this if you know of any

Bytell does that but with many extra tricks up its dirty sleeve https://github.com/skarupke/flat_hash_map/blob/master/bytell_hash_map.hpp

This is not linear probing. This is an exponential probing. The way he has improved performance is by precomputing the jump distances for finding the next free spot. The largest entry in his jump_distances array is large enough to accomodate a very large hash map. Typically when people say linear probing, they mean that the next spot to be checked is a linear function of the previous spot. This is what leads to clustering. In his case, the next free spot is not a linear function of the previous spot (except in the case of the first 16 entries). He uses triangular number sums beyond that which is essentially an exponential function. The fact that he calculates the jump distances using an offset into an array doesn't make this linear probing

Hello friends, good time, honestly, I am seventeen years old, I learned C++ in a preliminary way, but I don't pursue a specific field or goal with it, and I don't want to choose my field before it's too late. The atmospheres that I had, the field of front-end is less educational and I chose c++ just to enter the world of programming faster and I took Jolo, but I am not really pursuing a specific field with it, should I continue with c++ or enter the web field On the other hand, I am interested in working with other technologies and I would like to know how a site can be raised from zero to one hundred and to learn more practical programming than to get to know the logic of programming. Thank you for your help.

C++ is not the first language to use when it comes to web. As far as I know in web it mostly used on high load backend servers (like search engines), and even there it is often being replaced with other technologies because of the complexity to write safe code in C++. If your main focus is web, I would suggest trying languages/technologies related to web sooner than later, C++ (or maybe even C) may be nice to learn to understand how things work under the hood, but the first thing you would need in practice is the technologies that are prevalent in the area of your interest. And if you don't want to choose now, then just learn whatever language is fun for you. The core concepts are very similar between most of the languages, learning the second language is far easier than learning the first one.

Hay Is anyone here know about MIPS Architecture model 🙂

Hay Is anyone here know about MIPS Architecture model 🙂

are empty constructors common in C++?

Yes, but people usually default them in that case. class A { A() = default; ... }; The reason to have such constructors is usually that all the members are user-defined types (classes) that initialize themselves. In very rare cases initialization can be skipped to save a few operations. Or people can also rely on the fact that POD types (not sure what is the correct name for them) are zero initialized in some scenarios. Defaulting is better than defining an empty constructor because it allows some optimizations (defaulting is technically a bit different than having an empty constructor from the compiler point of view).

I have a question about the arrays: a[7][5] is the same as a[7*5] ?

I have a question about the arrays: a[7][5] is the same as a[7*5] ?

Guys anyone working with open-source project that want someone to contribute?

Hello, how I get: wchar_t *example=L"ñ"; printf( "%x\n", (unsigned)example[0]); but with: wchar_t *example=argv[1]; and get the same with the character "ñ"

If it’s standard C, argv[1] is encoded in ASCII, and you can’t really get wide character from it

I try to do this: int convert_to_opcodes(char *parts) { wchar_t *parts0; //wcstombs(parts, parts0, 1); //I get c3 //mbrtowc(parts0, parts,1,NULL); //I get c3 mbtowc(parts0, parts,1); //I get c3 return wctob(parts0[0]); // I get c3 //return (unsigned)parts0[0]; //normal method but the same, c3 }; int main(void) { // not the same, I get c3 with "ñ" printf("Opcode: %x\n", convert_to_opcodes("ñ")); // with "ñ" I get c3 // simple example wchar_t *example = L"ñ"; printf("Opcode: %x\n", (unsigned)example[0]); // with "ñ" I get f1 <- this is correct return 1; }

I have these results on my machine: Opcode: ffffffc3 Opcode: c3 It seems that I can't get 0xf1 to recreate that. If you want wchar_t * from argv, try GetCommandLineW if you're on Windows

Ok I do it in console (windows), and I get f1, for some reason... but when I run in sublime I get c3 with the function and the simple example a get f1

I have these results on my machine: Opcode: ffffffc3 Opcode: c3 It seems that I can't get 0xf1 to recreate that. If you want wchar_t * from argv, try GetCommandLineW if you're on Windows

In sublime I don't know* how that build the code, but when I build in Windows I use $ gcc -o example.exe example.c

How can I convert this: int main(int argc, char *argv[]) { char str[] = "Hola"; char *ptr = (char *)(str[0] & 0xFF); //the program stop printf("%s\n", ptr); } I want to get the first string of str 'H' or other, example 'a' or 'o' and convert to char...

The code you've provided seems to have some misunderstandings and issues. Let's break down what's wrong with it: int main(int argc, char *argv[]) { char str[] = "Hola"; char *ptr = (char *)(str[0] & 0xFF); //the program stop printf("%s\n", ptr); } 1. Type Mismatch: The main issue in this code is a type mismatch. str[0] is of type char, and when you perform str[0] & 0xFF, you're performing a bitwise AND operation with an integer constant 0xFF (which is 255 in decimal). The result of this operation is an integer value (0 to 255). Then you're trying to assign this integer value to a pointer of type char * (i.e., char *ptr). This is incorrect because an integer value cannot be directly assigned to a pointer. 2. Undefined Behavior: Even if you were to cast the integer value to a pointer type, attempting to print the string pointed to by ptr using %s in the printf function would lead to undefined behavior. The value resulting from the bitwise AND operation is not guaranteed to be a valid memory address, and attempting to interpret it as a C-style string would result in unpredictable behavior, including program crashes or incorrect output. Here's how you might fix the code to make it work correctly: int main(int argc, char *argv[]) { char str[] = "Hola"; char *ptr = &str[0]; // Assign a valid memory address to the pointer printf("%s\n", ptr); return 0; // Return 0 to indicate successful execution } In this corrected code, ptr is assigned the address of the first character in the str array. This is a valid memory address, and printing the string starting from this address using %s in the printf function will work as intended. Additionally, don't forget to include a return 0; statement at the end of the main function to indicate successful program execution.

I found this list of fundamentals that would be very important to have in order to have a solid foundation in programming, among them, what do you think should be the start for a total beginner? Data Structures and Algorithms Computer Architecture Theory of Computation Operating Systems Compilers Discrete Math

I found this list of fundamentals that would be very important to have in order to have a solid foundation in programming, among them, what do you think should be the start for a total beginner? Data Structures and Algorithms Computer Architecture Theory of Computation Operating Systems Compilers Discrete Math

And it depends on what your end goal is

Are you able to program something?

I found this list of fundamentals that would be very important to have in order to have a solid foundation in programming, among them, what do you think should be the start for a total beginner? Data Structures and Algorithms Computer Architecture Theory of Computation Operating Systems Compilers Discrete Math

Well studying compilers in-depth is not useful unless you want to work on them or related fields, so I'd say the number one priority is data structures and algorithms, then operating systems and computer architecture, then everything else

woww thank you very much seriously, would you have any book recommendations for data structures and algorithms?

Hi everyone! Is here a channel with cpp vacancies?

That would be so cool to make this channel