Prime Numbers

primes

void printPrimeNumbers(unsigned int num) {

    std::list<unsigned int> listPrimes;
    listPrimes.push_back(2);
    listPrimes.push_back(3);
    listPrimes.push_back(5);
    listPrimes.push_back(7);
    std::string sNum;
    unsigned int iNum;
    unsigned int sqrt1;
    for (unsigned int i = 10; i < num; i++) {
        sNum = intToString(i);
        iNum = charToInt(sNum[sNum.size() - 1]);
        if ((iNum == 2) || (iNum == 4) || (iNum == 5) || (iNum == 6) || (iNum == 8) || (iNum == 0))
            continue;
        else if (((i % 3) == 0) || ((i % 7) == 0))
            continue;
        else {
            sqrt1 = sqrt(i);
            for (std::list<unsigned int>::iterator it = listPrimes.begin(); it != listPrimes.end(); it++) {
                //std::cout << (*it) << ":" << sqrt1 << std::endl;
                if ((*it) > sqrt1) {
                    listPrimes.push_back(i);
                    break;
                }
                if ((i % (*it)) == 0)
                    break;
            }
        }
    }

    std::cout << "Total: " << listPrimes.size() << std::endl;
    unsigned int uiCount = 1;
    std::string sSum = "0";
    for (std::list<unsigned int>::iterator it = listPrimes.begin(); it != listPrimes.end(); it++) {
        if ((*it) > 5000)
            break;
        std::cout << intToString(*it) << std::endl;
        sSum = add(sSum, intToString(*it));
        sSum = removePrecedingZeros(sSum);
        //if (uiCount == 250)
        //    break;        
        uiCount++;
    }
    std::cout << "sum of numbers is: " << sSum << std::endl;
}