Dual core programming?

[amberleef]

Hi i have a permutation program that i think would run faster if i used the 2 cores on my cpu, but after having a look around it seems confusing to grasp the idea of how i can acomplish this. Below is the code for my permutations, if someone could give me an example then it might be easier for me to understand, many thanks :)

// next_permutation.cpp
// next_permutation : Change the order of the sequence to the
//                    next lexicograhic permutation.
// disable warning C4786: symbol greater than 255 character,
// okay to ignore
#pragma warning(disable: 4786)

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <functional>

using namespace std ;

int main()
{
    const int VECTOR_SIZE = 20;

    // Define a template class vector of strings
    typedef vector<string> StrVector ;

    //Define an iterator for template class vector of strings
    typedef StrVector::iterator StrVectorIt ;

    //Define an ostream iterator for strings
    typedef ostream_iterator<string> StrOstreamIt;

    StrVector Pattern(VECTOR_SIZE) ;

    StrVectorIt start, end, it ;

    StrOstreamIt outIt(cout," ") ;

    start = Pattern.begin() ;   // location of first
                                // element of Pattern

    end = Pattern.end() ;       // one past the location last
                                // element of Pattern

    //Initialize vector Pattern  	
    Pattern[0]  = "TOM";
    Pattern[1]  = "DICK";
    Pattern[2]  = "HARRY";
    Pattern[3]  = "PAUL";
    Pattern[4]  = "PETER";
    Pattern[5]  = "STEVEN";
    Pattern[6]  = "JOHN";
    Pattern[7]  = "IAN";
    Pattern[8]  = "GEORGE";
    Pattern[9]  = "KEVIN";
    Pattern[10] = "SCOTT";
    Pattern[11] = "STUART";
    Pattern[12] = "BRIAN";
    Pattern[13] = "DAVID";
    Pattern[14] = "SEAN";
    Pattern[15] = "STEVIE";
    Pattern[16] = "MARK";
    Pattern[17] = "RYAN";
    Pattern[18] = "RUDOLF";
    Pattern[19] = "SANTA";

    

    // print content of Pattern
	cout  << "Pattern: " ;
    cout << "Before calling next_permutation:\n" << "Pattern: " ;
    for(it = start; it != end; it++)
        cout << *it << " " ;
    cout << "\n\n" ;

    // Generate all possible permutations

    cout << "After calling next_permutation:" << endl ;
    while ( next_permutation(start, end) )
    {
        copy(start, end, outIt) ;
        cout << endl ;
    }
	return 0;
}

[Moschops]

For a similar discussion http://www.cplusplus.com/forum/beginner/57165/

[amberleef]

thanks for the quick reply but there is only minor talk about it on that link. :)

[Moschops]

The information to pick out is: threads, with options to express your wishes for running on more than one core.

[Gaminic]

What part of the code do you think would be fit for parallel execution?