Linked list taking input

I am not able to take input form file as shown in tutorial.
How can i do the same in windows

in this video sir is not taking input form any file

they are just typing the input in cmd

if you want to take input from file
use this
freopen(“filename.txt”,“r”,stdin);
save the file in same directory with the code.cpp file

https://online.codingblocks.com/app/player/54863/content/151576/7151/lecture
In this lecuture sir said that we cannot see the front of the integer

what does it means???
front of interger
are you talking about this doubt or not??