To compile and build executables do

make

Code for problem 1 first part (sorting random numbers) is in samplesort.c

Run it with

mpirun -np xyz ./samplesort n weak/strong 

where n is the number of random numbers and weak means each of the np processes will sort n numbers, while strong (scalability) means the n numbers will be
equally divided among the np processes.

Code for problem 1 second part (reading from disk, sorting and writing to disk) is 
in samplesortdisk.c

Run it with 

mpirun -np xyz ./samplesortdisk input_filename output_filename

The input_filename is one of the files provided without the path. For example
to sort the data in sort_data_alt.dat just type

mpirun -np xyx ./samplesortdisk sort_data_alt.dat someoutputfilename

The paths to the input and output filenames are hardcoded as constants at
the top of samplesortdisk.c. By default the output file (with the sorted numbers)
will be written into my
folder in ciwater4-0 but that can be changed by editing the OUTPUT_PATH constant
at the top of samplesortdisk.c

The jobs used to obtain runtimes are called samplesortxyz.pbs where xyz is the 
number of cores they pass as an argument to mpirun above.

Code for problem 2 is in graphcoloring.c

Run it with

mpirun -np xyz ./graphcoloring input_filename output_filename

where the input_filename is one of the given files representing a graph and
the output_filename contains the color assigned by Jones-Plassmann to each
vertex as well as the largest color assigned.

Notice that some of the files are in a binary format. I used the translation code
provided by cmu to translate those to the normal format.

For example DSJC1000.9.col.b was converted to DSJC1000.9.col and similarly
flat1000.76.col.b was converted to flat1000.76.col.

The input_filename is just the filename and is relative to my directory containing 
all these graph files. Change INPUT_PATH at the top of graphcoloring.c to point to
a different location. Similarly the OUTPUT_PATH constant at the top point to a
location somewhere in my account but it can be changed.

Jobs to compute strong scaling are in files called gcgraphfilenp.pbs. 
For example gcle450_5a8.pbs (8 cores). Jobs to compute weak scaling are in 
files called gcle450_5aorborcversusqueensnp.pbs.

One note about debugging: At the top of each of the .c files there are a 
series of directives that start with DEBUG_XYZ. If defined to be 1 they will
allow for debugging throughout the code. I set them to 0 after testing.