Traveller salesman problem

build a system using only Java that solves travelling salesman problems. The travelling salesman problem is to go to each city exactly once and return to the start. Solving the problem should give a path and the length of the path. There are optimal solutions, that is solutions with the shortest path. Sample files are provided below. They have n lines for n cities. The first integer in the line is the city number (starting with 1 and ending with n) and the second and third integers are the X and Y coordinates of the city. Distance is standard Euclidean distance. The system should solve the three training sets