摘要： Problem Description 某省调查城镇交通状况，得到现有城镇道路统计表，表中列出了每条道路直接连通的城镇。省政府“畅通工程”的目标是使全省任何两个城镇间都可以实现交通（但不一定有直接的道路相连，只要互相间接通过道路可达即可）。问最少还需要建设多少条道路？ Input 测试输入包含若干测 阅读全文

摘要： Description Severe acute respiratory syndrome (SARS), an atypical pneumonia of unknown aetiology, was recognized as a global threat in mid-March 2003. 阅读全文

摘要： Description There are so many different religions in the world today that it is difficult to keep track of them all. You are interested in finding out 阅读全文