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Description Farmer John's N (1 ≤ N ≤ 10,000) cows are lined up to be milked in the evening. Each cow has a unique "grumpiness" level in the range 1... 阅读全文
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Description windy学会了一种游戏。对于1到N这N个数字，都有唯一且不同的1到N的数字与之对应。最开始windy把数字按 顺序1，2，3，……，N写一排在纸上。然后再在这一排下面写上它们对应的数字。然后又在新的一排下面写上它们 对应的数字。如此反复，直到序列再次变为1，2，3，……，N 阅读全文
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Alice and Bob have a set of N cards labelled with numbers 1 ... N (so that no two cards have the same label) and a shuffle machine. We assume that N i 阅读全文
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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 小C有一个集合S，里面的元素都是小于M的非负整数。他用程序编写了一个数列生成器，可以生成一个长度为N的数列，数列中的每个数都属于集合S。 小C用这个生成器生成了许多这样的数列。但是小C有一个问题需要你的帮助：给定整数x，求所有可以生成出的，且满足数列中所有数的乘积mod M的 阅读全文
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Problem Description The picture indicates a tree, every node has 2 children. The depth of the nodes whose color is blue is 3; the depth of the node wh 阅读全文
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Description 你被要求设计一个计算器完成以下三项任务： 1、给定y,z,p,计算Y^Z Mod P 的值； 2、给定y,z,p，计算满足xy≡ Z ( mod P )的最小非负整数； 3、给定y,z,p，计算满足Y^x ≡ Z ( mod P)的最小非负整数。 你被要求设计一个计算器完成以 阅读全文
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Description Little Y finds there is a very interesting formula in mathematics: XY mod Z = K Given X, Y, Z, we all know how to figure out K fast. Howev 阅读全文
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Description Given a prime P, 2 <= P < 231, an integer B, 2 <= B < P, and an integer N, 1 <= N < P, compute the discrete logarithm of N, base B, modulo 阅读全文