travelling salesman problem

http://xiru.org/blog/python-genetic-algorithms

http://www.iwr.uni-heidelberg.de/groups/comopt/software/TSPLIB95/

TSPLIB is a library of sample instances for the TSP (and related problems)
from various sources and of various types.
Symmetric traveling salesman problem (TSP)
Given a set of n nodes and distances for each pair of nodes, find a
roundtrip of minimal total length visiting each node exactly once. The
distance from node i to node j is the same as from node j to node i.
-> TSP data
Best known solutions for symmetric TSPs

http://www.tsp.gatech.edu/world/countries.html

We list below 25 TSP instances taken from the World TSP. For these
instances, the cost of travel between cities is specified by the Eulidean
distance rounded to the nearest whole number (the TSPLIB EUC_2D-norm). The
TSPs range in size from 29 cities in Western Sahara to 71,009 cities in
China; they provide additional tests to complement the TSPLIB collection.
The TSPs were derived from data contained in the National Imagery and
Mapping Agency database of geographic feature names.

We will be most happy to report any improved tours or improved lower bounds
that you may find.  A summary of the current solution status for the
instances can be found here.

http://www.gcd.org/sengoku/docs/arob98.pdf