How to get line of numbers from file and ignore first number?

Question

So, lets say we have a text.txt file with these numbers:

4 5 15 10 20 5 5 15 10 20 25

In the above example, the first numbers in the row describe how many numbers are in that row. The rest of the numbers are the numbers I am interested in (I will be sorting them in a later part of the code, but that is not where my question focuses).

My issue is, how can I best go about taking each row of numbers (ignoring the first number), placing them into a array, and then moving onto the next line and doing the same thing (placing them into an array, that will be later sorted)?

All my google searching points to doing this with strings via getline, and nothing really points to handling it with ints. Hope someone on here can help point me in the right direction.

Below is the basic code I would use to open the file:

#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    int a;

    ifstream inputfile;
    //declare an input file
    inputfile.open("text.txt");

    while(//not sure best way to do this part)
    {
            //guessing I can use a for loop and place numbers in array 
            //based on first number in the row of numbers
    }

    return 0;
}

Answer 1

The most obvious way would probably be to read a line with std::getline, then put the string into a stringstream, and read numbers from there (ignoring the first, obviously).

Answer 2

I suggest the following approach:

std::string line;

// Keep reading lines of text from the file.
// Break out of the loop when there are no more lines in the file.
while (getline(inputfile, line)){

   // Construct a istingstream from the line of text. 
   std::istringstream ss(line);

   // Read the numbers from the istingstream.
   // Process the numbers as you please.
}