#include <iostream> #include <string> void fn(const std::string& in) { try { const int num = std::stoi(in); std::cout << (in[0] == '-' ? "negative " : "positive "); std::cout << (num == 0 ? "zero" : "number") << "\n"; } catch (...) { std::cerr << "Invalid input\n"; } } int main(int, char**) { std::string input; std::cin >> input; fn(input); return 0; }

If i use other number.. Like -5 or 5 then..?

Can you write hello world ???

Can you write hello world ???

float v; std::cout<<":>"; std::cin>>v; std::cout <<"Output " <<(v>=0f?"positive ":"negative ") <<((v==0f || v==-0f) ? "zero" : "number") <<std::endl;

float v; std::cout<<":>"; std::cin>>v; std::cout <<"Output " <<(v>=0f?"positive ":"negative ") <<((v==0f || v==-0f) ? "zero" : "number") <<std::endl;

#include <iostream> #include <string> void fn(const std::string& in) { try { const int num = std::stoi(in); std::cout << (in[0] == '-' ? "negative " : "positive "); std::cout << (num == 0 ? "zero" : "number") << "\n"; } catch (...) { std::cerr << "Invalid input\n"; } } int main(int, char**) { std::string input; std::cin >> input; fn(input); return 0; }

does not work

and you need to write 0.f, otherwise i searches the literal operator f

It is pretty much head compiled, what doesn't work?

the logic, since bool bar() { return -0.0f == 0.0f; }is compiled to bar(): mov eax, 1 ret https://godbolt.org/z/zHzLD_

Try with > or <

@ollirz we can use if else statement..?

@ollirz we can use if else statement..?

yes you can, void fn(const std::string& in) { try { const int num = std::stoi(in); if (in[0] == '-') { std::cout << "negative "; } else { std::cout << "positive "; } if (num == 0) { std::cout << "zero\n"; } else { std::cout << "number\n"; } } catch (...) { std::cerr << "Invalid input\n"; } } I'd recommend getting a good book to learn programming

remove it then, however error handling will be no longer present what should be print in case someone enters hello world ?

Catch statement will run

Hello is no number, so its neither positive nor negative

remove it then, however error handling will be no longer present what should be print in case someone enters hello world ?

/saved

Can i inbox u?

Can you write a programme that print what you write in it?

I want to measure the execution time of a malloc across multiple machines

On each machine, execute malloc 10000 times and divide by 10000 the time taken, using std::chrono from C++ may help you in making that accurate enough

It's in pure C, not C++...

I say "malloc" but i mean any function, it's just an example

I say "malloc" but i mean any function, it's just an example

Function calls cost how long it takes to switch context and change the execution poinher

You can use any C function in C++, I don't see the issue, C++ gives far simpler and better results when benchmarking even C

A good compiler inlines most function calls

When possible without changing meaning

My goal is to find a relation between the clock cycles needed for the function execution and the time taken based on the CPU speed. Using RDTSC i got different number of ticks for a single malloc on different machines (24 - 129).

Should malloc require same clock cycles on all CPUs?

Should malloc require same clock cycles on all CPUs?

Not at all

So, it depends on?

So, it depends on?

CPU model, CPU instruction set, kernel, frequency of memory, eventual cache misses, virtual memory layout

U mean user input

Got it

A good compiler inlines most function calls

It's not that easy. Inlining is not always beneficial

And you can't figure the assignment?

This is not assignment

My goal is to find a relation between the clock cycles needed for the function execution and the time taken based on the CPU speed. Using RDTSC i got different number of ticks for a single malloc on different machines (24 - 129).

https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/ia-32-ia-64-benchmark-code-execution-paper.pdf If not, use profilers !!!