Question

how to input

1 2  
4 5 4 2 3  
1 2 1 1 1

to cmd?
I don’t want “1 2” to be read when I press “Enter” but to go to next line and write “4 5 4 2 3”

Answer 1

I’m just doing guesses here, since you really didn’t give me much to work with, but did you consider using the escape character () to escape newlines?

Alternatively, just create a loop that keeps reading until you enter an empty line:

string line;
do {
    cin >> line;
} while (line.size() > 0);