Generalized Orienteering Problem datasets

=== File format
The data files first have a line with four space-separated values:
- Number of vertices (n)
- Number of attributes for each vertex (m)
- The starting vertex (0-indexed)
- The ending vertex (0-indexed)
Sometimes this line has a fifth value, which should be ignored.

Next, there are n lines. Each line has n space-separated distances.
Together, these form the symmetric distance matrix of the complete graph
connecting the n vertices.

Finally, there are n lines, each of which contains m space-separated
reward values. There are the rewards for visiting the n vertices.

=== Files
The file 4china27.gop contains the base graph for the "touring in China"
problem instance that has been tested in the GOP literature. To obtain
the exponent values and distance limits for the 25 problem instances
associated with this graph, refer to Table 6 of the paper.

The files op1c.gop, op2c.gop, op3c.gop, op5c.gop, and op6c.gop are the
5 testing instances from Tsiligirides (1984) and Chao (1993). They have,
respectively, 21, 32, 33, 66, and 64 vertices. To obtain
the distance limits associated with the 89 problem instances associated with
these graphs, refer to Table 7 of the paper.

The remaining problem graphs, of the form #NAME#.gop, are the 126 testing
instances derived from 42 TSPLib graphs. The first number is the score
generation procedure for the graph, and the remainder of the filename is the
name of the TSPLib instance used to create the graph. The distance limits
associated with these instances are found in Table 8 of the paper.
