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[codeforces 339]E. Three Swaps 试题描述 Xenia the horse breeder has n (n > 1) horses that stand in a row. Each horse has its own unique number. Initially, 阅读全文
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[codeforces 339]D. Xenia and Bit Operations 试题描述 Xenia the beginner programmer has a sequence a, consisting of 2n non-negative integers: a1, a2, ..., 阅读全文
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[codeforces 360]A. Levko and Array Recovery 试题描述 Levko loves array a1, a2, ... , an, consisting of integers, very much. That is why Levko is playing w 阅读全文
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[codeforces 339]C. Xenia and Weights 试题描述 Xenia has a set of weights and pan scales. Each weight has an integer weight from 1 to 10 kilos. Xenia is go 阅读全文
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[codeforces 317]A. Perfect Pair 试题描述 Let us call a pair of integer numbers m-perfect, if at least one number in the pair is greater than or equal to m 阅读全文
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Day 7 上午看看数学书，老师让我把导数相关的概念学了。这也没有多高大上，就是一坨公式需要背，什么 (a)' = 0 啦，什么 (xn)' = n·xn-1 啦，什么 sin'(x) = cos(x)，cos'(x) = -sin(x) 啦，什么 [f(x) + g(x)]' = f'(x) + 阅读全文