摘要：
There is a company that has N employees(numbered from 1 to N),every employee in the company has a immediate boss (except for the leader of whole compa 阅读全文
摘要：
During the War of Resistance Against Japan, tunnel warfare was carried out extensively in the vast areas of north China Plain. Generally speaking, vil 阅读全文
摘要：
A lot of battleships of evil are arranged in a line before the battle. Our commander decides to use our secret weapon to eliminate the battleships. Ea 阅读全文