How to split a string into integer array in c++?

Question

I am new to c++.My aim is to read a file containing all integers, like

1 2 3\\n 1 3 4\\n 1 2 4\\n

and

1,2 3,4 5,6\\n 1,3 3,4 3,5\\n 1,3 3,4 4,2\\n

I could use getline to read them, but how could I split it into an integer array. Like array[3]={1,2,3} and array2={1,2,3,4,5,6} for the first line reading result? Sorry I forgot to mention that I was trying to not use the STLs for C++

Answer 1

You can do it without boost spirit

// for single line:
std::vector<int> readMagicInts(std::istream &input)
{
    std::vector<int> result;

    int x;
    while(true) {
       if (!(input >> x)) {
           char separator;
           input.clear(); // clear error flags;
           if (!(input >> separator >> x)) break;
           if (separator != ',') break;
       }
       result.push_back(x);
    }

    return result;
}

std::vector<std::vector<int>> readMagicLinesWithInts(std::istream &input)
{
    std::vector<std::vector<int>> result;

    std::string line;
    while (std::getline(input, line)) {
        std::istringstream lineData(line);
        result.push_back(readMagicInts(lineData));
    }
    return result;
}