Why there is str.at(n) function in c++ when we can simply using indexing i.e. str[n] ???

Thanks.

I have weird question. How to write multithreading txt file parser which can work faster then 1 thread version? I tried to do it in few ways but I see that processing speed sucks.

I use 1 thread to read and push to queue and in another thread I get front of the queue and parse but it still slower Something like 40%-50% lose.

#include <stdio.h> #include <string.h> int main() { char a[20]; int len,i,upper,lower,num,sym; upper=lower=num=sym=0; scanf("%s",&a); len=strlen(a); for(i=0;i<=len;i++) { if(a[i]>='A'&&a[i]<='Z') { upper=1; } else if(a[i]>='a'&&a[i]<='z') { lower=1; } else if(a[i]>='0'&&a[i]<='9') { num=1; } else sym=1; } { int sum=upper+lower+num+sym; if(strlen(a)<6||sum==1) { printf("Not safe"); } if(sum==2) { printf("Medium Safe"); } else printf("Safe"); } return 0; }

Guys why is sym=1 when I input 1234567

Guys why is sym=1 when I input 1234567

Because you set it to one in else sym=1

Because you set it to one in else sym=1

😂I found the problem.I set i<len wrong

switch ("operator") { ERROR switch quantity not an integer

switch ("operator") { ERROR switch quantity not an integer

just what it says :)

just what it says :)

meaning

Hello i need help with formula forFinding The difference areas of two rectangles when they intersect. Here is my version of the formula subtraction area=area1shape-area2shape+crosssectional area? It is correct?

meaning

You haven't put the correct thing into the switch

Hello i need help with formula forFinding The difference areas of two rectangles when they intersect. Here is my version of the formula subtraction area=area1shape-area2shape+crosssectional area? It is correct?

Yes this is correct except that the area of intersection is not called cross sectional area. Please stick to questions related to C/C++

between char[] ,std::array<> and std:: vector<char> which one is better to use as packet buffer when handling socket in c++

Anybody has any idea how to find square root of a number. I want to know the logic to code the program

between char[] ,std::array<> and std:: vector<char> which one is better to use as packet buffer when handling socket in c++

You should use either char [] or std::array<char, size>. Generally for buffers being passed across program boundaries, you should stick to types that are PODs and trivial. Vector is not though it has a standard layout. So you shouldn't use a vector.

I have some doubts

I am unable to include windows.h

in vscode and vs studio

any idea to fix this I thought about windows sdk ?

Anybody has any idea how to find square root of a number. I want to know the logic to code the program

?

Anybody has any idea how to find square root of a number. I want to know the logic to code the program

Try it: square root of x = to x^½, And x^n = exp(n * log(x)), so x^½ = exp(0.5 * log(x)). Perhaps it works🤕

Ok Thanks!

I don't think it's working....

Anybody has any idea how to find square root of a number. I want to know the logic to code the program

Do an inverse square root and multiply your number by it. There are plenty of videos on the web that explain how to do a fast inverse square root

(only works with IEEE754 as it is basically a trick to get an estimate of log(x) and then you use Newton's method to refine it)

Yes this is correct except that the area of intersection is not called cross sectional area. Please stick to questions related to C/C++

I'm sorry, but thanks for your answer

(only works with IEEE754 as it is basically a trick to get an estimate of log(x) and then you use Newton's method to refine it)

Ohk Thanks 👍

Hello, I have a question. How can I make the program round a number of 2 decimals places from 5? For example, if the final number is 33.105, I want the program to show 33.11.

Hello everyone I would like to create function with template iterator (like this std::list<T>::iterator) but got was not declarated error (10 line) Could someone suggest solution ? https://godbolt.org/z/7eEchn7sK

Hello everyone I would like to create function with template iterator (like this std::list<T>::iterator) but got was not declarated error (10 line) Could someone suggest solution ? https://godbolt.org/z/7eEchn7sK

You have to define the overloaded printLists function (i.e. the one taking the iterators) before the printlLists function that takes two std::list arguments.

You have to define the overloaded printLists function (i.e. the one taking the iterators) before the printlLists function that takes two std::list arguments.

You also have to use typename before std::list<T>::iterator to tell the compiler that it is a typename. By default the compiler will assume that it is not a typename

You have to define the overloaded printLists function (i.e. the one taking the iterators) before the printlLists function that takes two std::list arguments.

why? if i delete templates everything works ok

why? if i delete templates everything works ok

That is how templates work. The problem is that with templates, when you call printLists with 4 arguments, it will see only the printLists with2 arguments and say that the arguments don't match. This is one of the errors that you got in GodBolt link that you sent The other errors are related to the missing typename keyword before the parameters in your overloaded function. typename std::list<T>::iterator l1_it and so on. This will inform the compiler that iterator is a typename and not some static value

That is how templates work. The problem is that with templates, when you call printLists with 4 arguments, it will see only the printLists with2 arguments and say that the arguments don't match. This is one of the errors that you got in GodBolt link that you sent The other errors are related to the missing typename keyword before the parameters in your overloaded function. typename std::list<T>::iterator l1_it and so on. This will inform the compiler that iterator is a typename and not some static value

It seems like I know nothing. where should I put typename std::list<T>::iterator l1_it? I can write you to PM if you don't mind

It seems like I know nothing. where should I put typename std::list<T>::iterator l1_it? I can write you to PM if you don't mind

template<typename T> void printLists(typename std::list<T>::iterator& l1_it, const typename std::list<T>::iterator l1_it_end... and so on for the remaining 2 parameters

template<typename T> void printLists(typename std::list<T>::iterator& l1_it, const typename std::list<T>::iterator l1_it_end... and so on for the remaining 2 parameters

Thanks

I hope someone can help

line 54: you have to assign an initial value to a stack variable that is Null lines: 58,59: you have to print the call of the sum function like : cout<<sum(stack); Lines: 13,26,37,45: you have to pass stack parameter by reference not by value because it is changed in your functions like : (node* &stack) in the definition of functions

line 54: you have to assign an initial value to a stack variable that is Null lines: 58,59: you have to print the call of the sum function like : cout<<sum(stack); Lines: 13,26,37,45: you have to pass stack parameter by reference not by value because it is changed in your functions like : (node* &stack) in the definition of functions

Thank you very much for your help, you helped me a lot. I hope soon I understand this topic. Once again, thank you very much

You should use either char [] or std::array<char, size>. Generally for buffers being passed across program boundaries, you should stick to types that are PODs and trivial. Vector is not though it has a standard layout. So you shouldn't use a vector.

thank you

Thank you very much for your help, you helped me a lot. I hope soon I understand this topic. Once again, thank you very much

Welcome my friend There are many ways to implement these instructions It's okay if you are at the beginning but just to learn that this code can be greatly improved 🌸🌸

WAP that will take (m x n) positive integer inputs into a matrix of dimension m x n. Now replace all the duplicate integers by -1 in that matrix

how to do this? any idea?

WAP that will take (m x n) positive integer inputs into a matrix of dimension m x n. Now replace all the duplicate integers by -1 in that matrix

Whats mean WAP?

skip that part.

Ok

for(int i=0; i<m; i++) { for(int j=0; j<n; j++) { if(arr[i] != arr[j]) { arr[i][j] = -1; } cout<<arr[i][j]<<" "; }

I've tried this

for(int i=0; i<m; i++) { for(int j=0; j<n; j++) { if(arr[i] != arr[j]) { arr[i][j] = -1; } cout<<arr[i][j]<<" "; }

I have idea, but i dont know how effective it

tell me

Pass all values to std::set

And search values from this set

ok

Anybody has any idea how to find square root of a number. I want to know the logic to code the program

If it's a perfect square, you can use binary search till half the number

https://pastebin.com/SCtXTXcA What is the use of function initcounter(void) in line 9 and what does { counter = 0;} means in line 9 after declaring the function initcounter(void) ?

hi

https://pastebin.com/SCtXTXcA What is the use of function initcounter(void) in line 9 and what does { counter = 0;} means in line 9 after declaring the function initcounter(void) ?

the use is in line 36... please read the whole code before asking such questions

Do anyone know how to do thread safe in C++ without using mutex and synchronisation??

Do anyone know how to do thread safe in C++ without using mutex and synchronisation??

https://stackoverflow.com/questions/10770171/how-to-make-thread-synchronization-without-using-mutex-semorphore-spinlock-and

What is the best masterclasses to learn web development online?

Is there any clangd alternative which uses gcc?

Clangd is great but I encountered a lot of issues when using c++20.

Is there any clangd alternative which uses gcc?

gcc doesnt have lsp server

gcc doesnt have lsp server

That's bad

Clangd is great but I encountered a lot of issues when using c++20.

What version you use? I have crash on 13 version, but in 14 all works well

What version you use? I have crash on 13 version, but in 14 all works well

Neither of them worked. At least std::views does not work

https://www.godbolt.org/z/Kze41jejo

The code compiles with gcc, but clang or clangd cannot do it

The code compiles with gcc, but clang or clangd cannot do it

That means you need to wait implementation of that features

Is their any group discussion about opencv and deep learning in telegram?

That means you need to wait implementation of that features

Why can't gcc develop a lsp when clang has clangd? I dont have to wait if there is gccd 😂

hi what can make 2 printf with the \n in there end show in the same line and how to fix it

```c

printf("grind size ([C]ourse,[F]ine): \r\n"); scanf("%c", &grind_size); if(*grind_size == 'C' 'c'){ Course = 1; Fine = 0; } else if(*grind_size == 'F' 'f'){ Course = 0; Fine = 1; } printf("Bag weight (g): ","\r\n"); scanf("%f", &Bag_weight); G = Bag_weight; gram= 453.5924; pound = 0.0022; Lbs = G * pound;

when it run it show in the same line

grind size ([C]ourse,[F]ine):Bag weight (g):

#include <stdio.h> int main() { int length; int width; int Rectangle (length*width); printf("Enter the lenght : "); scanf("%d",&length); printf("Enter the width :"); scanf("%d",&width); printf("Total area : %d",&Rectangle); scanf("%d,%d",length,width); return 0; }

#include <stdio.h> int main() { int length; int width; int Rectangle (length*width); printf("Enter the lenght : "); scanf("%d",&length); printf("Enter the width :"); scanf("%d",&width); printf("Total area : %d",&Rectangle); scanf("%d,%d",length,width); return 0; }

Can i know how to calculate formula

Am using C/C++ compiler on mobile