2．　　设计一个启发式函数（最好是A*搜索函数）并编程实现，设计报告中必须给出函数的具体形式并说明设计思想（或分析为什么是A*算法）-2. Design a heuristic function (A * is the best search function), and Programming, design report must be given to the specific function and state forms design (or analyze why is A * algorithm)