当司机在一个地方没有油时，它应该在去那个地方去加油，走那条路为够更好的为他（她）服务，这条路又会经过那些地方， 系统会生成一个解决方案为司机提供一个选择的机会。-when the driver in a place without oil, it should go to those places to refuel and which way to go to better enough for him (her), this road will go through, system will generate a solution for the drivers an opportunity to choose.