Finding the shortest possible route is generally called the
Traveling Salesman Problem (TSP), a well-known NPhard problem in combinatorial optimization and the TSP has
been intensively studied in operations research and theoretical
computer science since the problem was first formulated as a
mathematical problem in 1930 [11]-[12]. The goal of the TSP
is to find the shortest path that visits all locations in a given list
exactly once and then returns to the starting location.