Yohoc

摘要： 题目： In the big cities, the subway systems always look so complex to the visitors. To give you some sense, the following figure shows the map of Beijin 阅读全文

摘要： 题目： Cutting an integer means to cut a K digits lone integer Z into two integers of (K/2) digits long integers A and B. For example, after cutting Z = 阅读全文