**1**- Rewrite program
`mkrandpfile.c`

discussed in section 5.3.1 to use the non-blocking`MPI_File_iwrite`

. Use function`MPI_Test`

to test if the writing process has completed every now and then, while calculating square roots of integers from 1 to 1,000,000 in the meantime. Square root is a very expensive, i.e., slow, arithmetic operation.