Whatever ones you like, it's merely an illustration of separating the processing from the I/O.
When you're happy with the processing, it's a REALLY REALLY simple job to replace the for loop iterating over an array of char pointers, with
- a while loop reading lines from a file, returning a filled in char array with say fgets()
- a while loop reading lines from the user, returning a filled in char array with say fgets()
- a getText response from reading a line of input from a GUI dialog
etc etc
