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Bessie and her friend Elsie decide to have a meeting. However, after Farmer John decorated his fences they were separated into different blocks. John' 阅读全文
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Alice is going to take all her savings out of the ATM(Automatic Teller Machine). Alice forget how many deposit she has, and this strange ATM doesn't s 阅读全文
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Jim has a balance and N weights. (1≤N≤20)(1≤N≤20) The balance can only tell whether things on different side are the same weight. Weights can be put o 阅读全文
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bobo has a sequence a 1,a 2,…,a n. He is allowed to swap twoadjacent numbers for no more than k times. Find the minimum number of inversions after his 阅读全文
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Given a number x, ask positive integer y≥2y≥2, that satisfy the following conditions: 1. The absolute value of y - x is minimal 2. To prime factors de 阅读全文
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nn pagodas were standing erect in Hong Jue Si between the Niushou Mountain and the Yuntai Mountain, labelled from 11 to nn. However, only two of them 阅读全文
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Given a sequence A with length n,count how many quadruple (a,b,c,d) satisfies: a≠b≠c≠d,1≤a<b≤n,1≤c<d≤n,Aa<Ab,Ac>Ada≠b≠c≠d,1≤a<b≤n,1≤c<d≤n,Aa<Ab,Ac>Ad. 阅读全文
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直接打表找规律 HazelFan is given two positive integers a,ba,b， and he wants to calculate amodbamodb. But now he forgets the value of bb and only remember the 阅读全文
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春天到了, HDU校园里开满了花, 姹紫嫣红, 非常美丽. 葱头是个爱花的人, 看着校花校草竞相开放, 漫步校园, 心情也变得舒畅. 为了多看看这迷人的校园, 葱头决定, 每次上课都走不同的路线去教室, 但是由于时间问题, 每次只能经过k个地方, 比方说, 这次葱头决定经过2个地方, 那他可以先去问 阅读全文