Reading From Files

Question

I was bit curious if I was going about this the wrong way. I am trying to read numbers from two different lists, sort the numbers, and then output ALL the numbers to a3rd file. I understand getline is probably not the best option but I still would like to use it.

list1 = 1,4, 5, 18

list2 = 2, 3, 15, 16

output = 1, 2, 3, 4,5, 7, 15,16 - what i should get

what i actually get - 1, 3, 5, 16

Here's a portion of the code

void sorted(std::ifstream &ifs, std::ifstream &ifs1, std::ofstream &ofs){
//while ((!ifs.eof()) & (!ifs1.eof())){

    //int number = 0;
    //int number1 = 0;
    std::string num1;
    std::string num2;
    //getline(ifs, num1);
    //getline(ifs1, num2);

    while(std::getline(ifs, num1) && std::getline(ifs1, num2)){
    int number = 0;
    int number1 = 0;
    std::stringstream ss1;
    std::stringstream ss2;
    ss1 << num1;
    ss2 << num2;
    ss1 >> number;
    ss2 >> number1;
        //while(ss1 >> number && ss2 >> number1)
        //{
            if (number < number1){
                ofs << number << std::endl;
                ss1 >> number;
                std::cout << "am i doing this right?";
            }
            else{
                ofs << number1 << std::endl;
                ss2 >> number1;
            }

        }

    }

Answer 1

You are discarding one number in each pair each iteration because your if (number < number1) ... else block only ever writes one of the two numbers out.

Try...

        if (number < number1){
            ofs << number << std::endl;
            ofs << number1 << std::endl;
            ...
        }
        else{
            ofs << number1 << std::endl;
            ofs << number << std::endl;
            ...
        }

Answer 2

getline is the best option, no doubt and it is always better than your commented line of code using eof. As Joachim mentioned in comment, you can first read the numbers from file to a std::vector container and call std::sort algorithm on top of vector.