摘要：
There is a public bike service in Hangzhou City which provides great convenience to the tourists from all over the world. One may rent a bike at any s 阅读全文
摘要：
A traveler's map gives the distances between cities along the highways, together with the cost of each highway. Now you are supposed to write a progra 阅读全文
摘要：
As an emergency rescue team leader of a city, you are given a special map of your country. The map shows several scattered cities connected by some ro 阅读全文