MPI Tests

In this lesson we will try to program the following:

1. Write a program that prints the rank of each process
2. Write a program such that each rank sends a string to the root, and root prints it
3. Write a program that computes the sum of ranks with a reduction
4. Write a program that computes the sum of vectors (one for each rank, with length 10 and values equal to the rank itself) with a reduction