In this assignment, you will modify your arguement broadcast routine to
communicate different datatypes with a single MPI broadcast (MPI_Bcast) call.
Have your program read an integer and a double-precision value from standard
input (from process 0, as before), and communicate this to all of the other
processes with an MPI_Bcast call. Use MPI datatypes.
Have all processes exit when a negative integer is read.
You may want to use these MPI routines in your solution:
MPI_Address
MPI_Type_struct
MPI_Type_commit
MPI_Type_free
MPI_Bcast