Well my Fifteen doesn't compile because get_int but I included cs50 library. What I am missing? Check the screen shot please. Thank you!
There is a new version of cs50.h for the upcoming semester at Harvard. After you ran update50, did you close all open terminals and open a new one(s)? From the picture I see that clang is using
-std=c11. That has changed, but you need to make sure the new environment is loaded. It might be easiest to restart the workspace (CS50 IDE -> Restart).
Looks like the new version of get_int() has an optional parameter to accept a prompt.