Convert from Python to c++?

/code

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Last edited on

Gee, posting a language that absolutely depends on indentation to make sense of it, without using code tags to preserve that indentation.

> Convert from Python to c++?
What kind of a question is that?

jonnin (11437)

he tried to use code tags, and failed, but at least he tried.

OP, the <> on the side edit bar will do code tags. You are close, wrap them in []
if the word tag were a tag it would be [tag] text [/tag]

This is a forehead-desk-smashing-question. Just write the thing in c++ (its a very simple problem) or, seeing as how its a common homework problem, get one of the 5 billion solutions in c++ to it online rather than try to convert it into what will be, after conversion, sloppy and poor c++ code. Python and C++ do things very differently, and trying to use the python way of doing things in c++ is not pretty. Trying to use the c++ way of doing things in python isnt very nice either. I am not picking on you, but conversion between languages should be towards the back end of last resorts; it is rarely a good plan for a simple code segment.

this gets you the primes from 0-100, as a starting point. Its not the best, but it was sitting around in my other people's homework folder.


  void pn()
  {	  
  unsigned long long i,j, s = 100; //s is how big a value you want to do.  c++ unsigned long long is 2^64-1  
//and cannot grow to be bigger like python's virtual integers. 
// bigger than 64 bit int needs more work, if you are doing something huge like encrypts. 
  vector<bool> pn(s,true); 
  for(i = 3; i < pn.size(); i+=2)
  {
     if(pn[i])
      for(j = i*2; j < pn.size(); j+=i)
         pn[j] = false; 	
  }	    
//below this line is just output.  above is finding the primes.  
  cout << 2 << endl;   //so you can use +=2 below.  
  for(i = 3; i < pn.size(); i+=2)
 	 if(pn[i])                                 //this is your isprime function. if pn[value] then its prime. 
       cout << i << endl;                   //if you are going to ask nonsense like 0 and 1, set those false. 
  }  
  int main()
  {
	 pn(); 	  
  }