摘要： http://poj.org/problem?id=3160题意读懂是关键，he chould choose to enter and give out a gift and hear the words from the recipient, or bypass the room in silence.通过这句话知道当收礼者给予的反应是负值时可以不加，flymouse decided to choose only one of those rooms as the place to start his journey and follow directed paths to visit on 阅读全文