Thread: Grabbing input text file using a stream

I wrote some code to grab input from a text file. I know specifically the format of the text file and the program was made tailored to only that specific format. I know this is pretty bad practice and if anyone can point me in the right direction, that would be great. But first I'd like to address a bug I'm getting.

My program basically takes in a .txt file and echoes back the file in exactly the same format. The bug is that I get a last line of zeroes. Can anyone explain to me why?

Code:

//Copies everything in an input file to cout
//usage: executable file1

#include <iostream>
#include <fstream>
#include <sstream>

using namespace std;

int main(int argc, char** argv)
{
  ifstream fin(argv[1]);
  string line;

  if (fin)
    {
      int nodes = 0;
      
      fin >> nodes;

      cout << nodes << endl;
    }

  //Grabs edge1, edge2, and cost
  while (fin)
    {
      //I need these to be int. I'm going to be doing something later with it.
      int x = 0, y = 0, z = 0;
      fin >> x >> y >> z;
      
      cout << x << " " << y << " " << z << endl;
    }
}

Here is the input for the .txt file.

Code:

50
0 1 14
1 2 13
3 9 11
9 11 5
1 2 3

Here is the output of the program.

Code:

50
0 1 14
1 2 13
3 9 11
9 11 5
1 2 3
0 0 0       //last line of zeroes