说明：  主要解决旅行商问题(traveling saleman problem,简称tsp，即已知n个城市之间的相互距离，现有一个推销员必须遍访这n个城市，并且每个城市只能访问一次，最后又必须返回出发城市，求解最短距离的遗传算法。
(mainly to solve the traveling salesman problem (traveling saleman problem, listed tsp, known cities n between the distance from the existing one salesman must traveled n this city, and visit each city only once, finally starting to return to the city, for the shortest distance from the genetic algorithm.)