C++ Reading fixed number of lines of integers with unknown number of integers in each line

Question

I\'m trying to read in data and solve simple problem, data :

3               - number of lines to read in
1 1
2 2 2
3 4 

after each line is

Answer 1

C++ gives you many tools:

• string is a class managing the lifetime of character strings.
• getline puts a line from a stream (up to the next newline) into a string.
• istringstream makes an istream out of a string
• istream_iterator iterates over an istream, extracting the given type, breaking on whitespace.
• accumulate takes iterators delimiting a range and adds together the values:

Altogether:

string line;
while (getline(cin, line)) {
    istringstream in(line);
    istream_iterator begin(in), end;
    int sum = accumulate(begin, end, 0);
    cout << sum << '\n';
}