Download the Difficult Problems Code and Results

The archive file diffprob.zip contains the files:

readme.txt general information
areash.pdf Computing the surface area of a Sears-Haack body
areash2.pdf Numerical details
areash.f90 Program for computing surface area
geopot.pdf What is geopotential altitude (and why?)
hydro.pdf Equations of hydrostatic equilibrium
oshock1.pdf Wave angle for a given Mach and deflection angle
oshock2.pdf Numerical details
oshock.f90 Program for computing oblique shock

None of these are what we call production programs. You can simply run them and modify them as needed to help you understand the problem.