GVFSnake算法相对好实现，且有相关的例子说明，代码中对各部分内容做了详细的说明，和Greedy算法相比，该算法具有很好的实用性-GVFSnake algorithm to achieve relatively good, and relevant examples, the code for each part of a detailed descr iption, and the Greedy algorithm, the algorithm has a good practical