一辆汽车加满油后可行驶n 公里。旅途中有若干个加油站。设计一个有效算法，指出应在哪些加油站停靠加油，使沿途加油次数最少。并证明算法能产生一个最优解。-A fill up the car after running kilometers n. The journey with a plurality of gas station. The design of an efficient algorithm, point out should be in which gas station refueled, make along the least number of refueling. And to prove that the algorithm can produce an optimal solution.