Before swap_char: Crogramming in P is hard.
After swap_char: Programming in C is easy.
Before swap_int_double: n=2, x=3.400000
After swap_int_double: n=3, x=2.000000
Before swap_pointers: *p=1, *q=3
After swap_pointers: *p=3, *q=1
Now p points to n. Very good!
Now q points to m. Very good!
Before swap_watch: Thusrday classes start at 13:45:00 and finish at 12:15:00
After swap_watch: Thusrday classes start at 12:15:00 and finish at 13:45:00