Reading array without knowing its size

[david_graham]

i know it may sound a bit stupid, but i'm stuck at the MERGSORT problem because i don't know how to read the input...

i have to read whitespace separated integers until the end of the line, but i don't seem to be able to do that..

can anyone help me?

[TripleM_sof]

scanf should suffice.. cplusplus.com/reference/clib ... dio/scanf/

[david_graham]

could you explain to me? i really don't know how to use only scanf to do that, as the problem doesn't specify the quantity of numbers.. thanks

[TripleM_sof]

That page specifies what scanf returns when reaches the end of file. So just read numbers in inside a while(true) loop, and break when scanf reaches the end of file.

[david_graham]

that didn't work...

i = 0;
while(true){
      if(scanf("  %d", &v[i++]) == EOF) break;
}

the numbers keep on being read even after pressing enter...

[TripleM_sof]

Well, pressing enter doesn't tell the program it has reached the end of the file - how does it know you aren't going to type in more numbers on the next line?

Either redirect the input from a file on the command line, which is probably a better idea anyway, or use ctrl-z to signify EOF when entering input.

[david_graham]

I got it. Thanks!