使用遗传算法求最短回路。用户输入信息在1.txt中。目前有6个城市，如果权值为-1，表示两个城市之间不可达。遗传算法会被执行5次。-Using genetic algorithm for the shortest loop. The user to enter information in the 1.txt. There are six cities, if the weight is-1, indicating that up between the two cities. Genetic