Question

My test file has data like this:

1
2
3
0
1, 2
3, 4
0, 0
4, 3
2, 1
0, 0

How would I separate the data by line but also separate each section of data by the zeros.

 ifstream data("testData.txt");
string line, a, b;


while(getline(data,line))
{
    stringstream str(line);
    istringstream ins;
    ins.str(line);
    ins >> a >> b;

    hold.push_back(a);
    hold.push_back(b);  
}

How do I separate them by the zeros?

Answer 1

So the lines are significant, and the zero-delimited lists of numbers are also significant? Try something like this:

std::ifstream data("testData.txt");
std::vector<int> hold;
std::string line;
std::vector<std::string> lines;

while(std::getline(data,line))
{
  lines.push_back(line);
  std::stringstream str(line);

  // Read an int and the next character as long as there is one
  while (str.good())
  {
    int val;
    char c;
    str >> val >> c;
    if (val == 0)
    {
      do_something(hold);
      hold.clear();
    }
    else
      hold.push_back(val);
  }
}

This isn’t very fault-tolerant, but it works. It relies on a single character (a comma) to be present after every number except the last one on each line.