Beginners - C++ Forum

Welcome to the beginner's forum in C++.com! In this forum, users can to talk about any topic related to C++ for non-expert audiences. Feel free to participate...

[2 replies] Last: How To Answer Questions in a Helpful Way Be gentle. Problem-relat... (by admin)

by Zolaboony

Console Closing Down (1,2,3,4,5,6,7)

Hi, i am new to C++ and have just written my "Hello World" program. It worked all right but the console/cmd closes down instantly. If you tell me why it is clos...

[120 replies] Last: It displayed "Hello world" after you pressed Enter. int c is a ... (by Duthomhas)

by kdrewes

search for words in a file

Hi, I have a program I'm currently working on where I'm trying to read a particular city from a file. Here is the content of the file below: Oakland : Lake ...

[2 replies] Last: What are you trying to do? Do you try to find multiple locations? Sinc... (by coder777)

by codinglexernewbie

how do i implement a for loop in a math interpreter

how do I implement loops in a math interpreter? it gets the tokens but discards them after reading them but I want to implement for loops and such, like > Σ(n...

[4 replies] Last: @seeplus i convert the expression using shunting-yard (by codinglexernewbie)

by AlexCantor

JSON C++

Using Visual C++ 2022 community edition to compile following JSON C++ program from book C++20 for Programmers by Deitel & Deitel, Published in 2022, chapter 9 p...

[no replies]

by ninja01

Why const int instead of just int

const int func(void) { return 3; } In code above, what is the need of const int as returned type instead of just int? Can you site a specific situ...

[5 replies] Last: A series about using const, starting with const local variables. https... (by George P)

by ninja01

Question 5 about optimization

Probably the last optimization question and it is about initialization Part I Consider the two snippet below: int main() { int nbr; } int main() { ...

[5 replies] Last: Herb Sutter is someone who I listen to when he mentions something C++:... (by George P)

by ninja01

About character sets

I looped through 512 characters and I realized that: my character set is 256. so it is not an 7-bit ascii. Instead, it is variant. My question is: Is there a...

[2 replies] Last: my cygwin compiler still produces smiley faces for those. if its just... (by jonnin)

by ninja01

Some sort of hack?

Can I check wether my operation system is 32/64 using the code below: switch(sizeof(int*)) { case 8: std::cout << "64-bit system" << std::endl; ...

[16 replies] Last: There are lots of web-pages with "simple code" on the internet that al... (by George P)

by ninja01

Question 3 about optimization

which one is better: for(int i=0;i<(int)strlen(bTitle);i++) or int titleLength = (int)strlen(bTitle); for(int i=0;i<titleLength;i++) I think ...

[7 replies] Last: If you change the size of a c-style string within the loop, then you'l... (by seeplus)

by ninja01

Question 1 about optimization

is there any way to test which of two algorithm is best in terms of speed/efficiency and number of instruction? Note: I am about to flood this forum with cou...

[10 replies] Last: See how timings were done in this thread https://cplusplus.com/forum/b... (by seeplus)

by UnkownUser

How to make sudoku16x16 as fast as possible

Good day , I need assistance in making my sudoku as fast as possible currently it completes it in 1163 seconds #include <iostream> #include <algorithm>...

[5 replies] Last: No. I use a 3d-array for the board... (by seeplus)

by ninja01

Question 4 about optimization

Consider the two code snippet below: int side ,s ,p; cout << "Enter square's side value -> " << endl ;cin >> side; s = side*side ; p = side*4 ; cout <...

[15 replies] Last: Yeah - but that was then and this is now as they say. I used to do in-... (by seeplus)

by ninja01

Question 2 about optimization

which one is better a>=6; or a>7 I think the a>=6 does two operations while a>7 does only one, so the second one is better. Am I wrong here?

[6 replies] Last: integer comparisons at assembler level tend to be based on a test inst... (by seeplus)

by ninja01

pointer to char related

Consider code below: int i = 3; int *pi = &i; double d = 5.2; double *pd = &d; char c = 'j'; char *pc = &c; cout << pi << endl; cout << pd <<...

[2 replies] Last: Thank you very much @Ganado) (by ninja01)

by ninja01

Unexpected behavior 2!

Consider the code below: int total; std::cin >> total; int ary ; for(int i=0;i<total;i++) ary = i; for(int i=0;i<total;i++) std::cout...

[9 replies] Last: It's not as straightforward as it looks because it interferes with the... (by Peter87)

by ninja01

A linux for programming

I never used a linux OS, I am open to the idea of using it lately, what is the best linux for programming you advice? thanks

[18 replies] Last: Got it, thank you everyone) always honored. (by ninja01)

by rozick1

Work around for limitation of template virtual member functions?

Hi I have a Message class which other classes inherit from. The inherited classes will need to have a serialisation member function. I would like to make these...

[1 reply] : You could use some special-case code for each class, or exploit that T... (by mbozzi)

by vonits23

checking if the inputs are valid Palindrome

How can I make this program work to determine whether these 5 palindromes are valid or not? #include <iostream> #include <string> struct Result { int...

[6 replies] Last: thank you guys :) (by vonits23)

by dvdlly

building a multilayer perceptron

Hello, I want to implement a simple multilayer perceptron for digit recognition. I have started to read the c++ primer 5th edition book 2 days ago so I am no...

[9 replies] Last: @dvdlly, I am well aware that the code you provided is a header file, ... (by lastchance)