摘要：
Problem DescriptionA lot of battleships of evil are arranged in a line before the battle. Our commander decides to use our secret weap... 阅读全文
摘要：
Problem DescriptionChinese always have the railway tickets problem because of its' huge amount of passangers and stations. Now goverme... 阅读全文
摘要：
Problem DescriptionAstronomers often examine star maps where stars are represented by points on a plane and each star has Cartesian co... 阅读全文