There are four input files, sample-ab.txt, sample-c.txt, sample-d.txt, and sample-e.txt. sample-ab.txt has 10000 vertices, sample-c.txt and sample-d.txt each have 30, sample-e.txt has 11 vertices. There are output files for sample-ab.txt run with MST and FASTTSP, while samples c-e were run with all 3 modes. The file sample-d.txt is the same as sample-c.txt, EXCEPT that it has been shifted up and to the right by 50, putting all vertices in Quadrant 1 of the graph. If you get the same answers when running samples c and d in MST mode, and sample c output is wrong, it's because you forgot to account for transitioning from one region to another. When running OPTTSP, if you get sample d right but sample c wrong, it's because you forgot that in FAST and OPT, you DO NOT consider the border between regions. The file sample-e.txt has 11 vertices selected from sample d; the vertices were selected so that our fast and optimal solutions give different output. This test case should help with debugging OPTTSP mode.