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摘要： 描述These are N cities in Spring country. Between each pair of cities there may be one transportation track or none. Now there is some cargo that should... 阅读全文

摘要： 描述In the game of Dungeons & Dragons, players often roll multi-sided dice to generate random numbers which determine the outcome of actions in the game. These dice come in various flavors and shapes, ranging from a 4-sided tetrahedron to a 20-sided isocahedron. The faces of an n-sided die, called 阅读全文

摘要： 描述Alex likes solving problems on WOJ (http://acm.whu.edu.cn/oak). As we all know, a beautiful balloon will appears when a problem is solved. Alex love... 阅读全文

摘要： DescriptionWe will use the following (standard) definitions from graph theory. Let V be a nonempty and finite set, its elements being called vertices (or nodes). Let E be a subset of the Cartesian product V×V, its elements being called edges. Then G=(V,E) is called a directed graph. Let n be a 阅读全文

摘要： 描述Some of the secret doors contain a very interesting word puzzle. The team of archaeologists has to solve it to open that doors. Because there is no ... 阅读全文