There are three source files barber.c$,$ customer.c$,$ and waiting room.c$.$ The files

barber.c and waiting room.c are compiled and linked together to build the executable

file barber, while the files customer.c and waiting room.c are compiled and linked

together to build the executable file customer. Write a makefile so you can just type

make to build the barber and the customer executable files.

Assume that after building the barber and the customer executable files, you modify

the file waiting room.c$.$ Then you type make again. What will you see on the screen

$($i$.$e$.$ the compiling$/$linking commands executed$)?$