摘要：
Problem Description ACboy很喜欢玩一种战略游戏，在一个地图上，有N座城堡，每座城堡都有一定的宝物，在每次游戏中ACboy允许攻克M个城堡并获得里面的宝物。但由于地理位置原因，有些城堡不能直接攻克，要攻克这些城堡必须先攻克其他某一个特定的城堡。你能帮ACboy算出要获得尽量多的 阅读全文
摘要：
There is going to be a party to celebrate the 80-th Anniversary of the Ural State University. The University has a hierarchical structure of employees 阅读全文
摘要：
A school bought the first computer some time ago(so this computer's id is 1). During the recent years the school bought N-1 new computers. Each new co 阅读全文