Being in main folder you can type
make
to create build
folder and build everything into it. To run one of executables you have to go to folder build
and run
mpirun -np [num_procs] [executable]
For example:
mpirun -np 4 ./1.1_HelloWorld.exe
Note: for 1.2_ReciprocalSum.exe you have to specify which number you are summing up to:
mpirun -np 4 ./1.2_ReciprocalSum.exe 1000000