Well case a is just assigning whatever the user types in, into the the first element of 'n' and it is assigned through typecast to "times".
Case b is the same, except the user has typed 2 characters, and they are stored in the first and second elements of 'n' Now when the function atoi operates on the array n, it takes both elements into account and converts it accordingly.
Case c is the same as case a, except the result is divided by 10. (Which is because the base time is set to 10ms, and case C is invoked when the user wants to specify a time which is 5-9, so if they put in 5 for 5ms, the variable is set with 5 X unit = 5 X 10ms, so they divide by 10.
errrrrrrrrr i think thats all right.
Megamox