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Description Bob and Alice started to use a brand-new encoding scheme. Surprisingly it is not a Public Key Cryptosystem, but their encoding and decodin 阅读全文
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Description We remind that the permutation of some final set is a one-to-one mapping of the set onto itself. Less formally, that is a way to reorder e 阅读全文
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Description 你有一个N*N的棋盘，每个格子内有一个整数，初始时的时候全部为0，现在需要维护两种操作： 命令 参数限制 内容 1 x y A 1<=x,y<=N，A是正整数 将格子x,y里的数字加上A 2 x1 y1 x2 y2 1<=x1<= x2<=N 1<=y1<= y2<=N 输出 阅读全文