This is a test problem solution backing a job interview.
The program reads a dependency tree from a structured text file, finds independent groups of nodes and prints them out. It also draws the graph to in an svg file and generates a graphviz input file for dot.
Most of the example files are borrowed (and processed into another format) from the graphviz gallery.
mkdir build; cd build; cmake ..; make; cd ..
build/bin/dep-graph example/simple.txt
It should print the independent graph node groups and produce the output.svg and the output.dot files.
output.svg:
To process the .dot file you need graphviz.
dot -Tpng output.dot > output.png