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``` The heat during the last few days has been really intense. Scientists from all over the Berland study how the temperatures and weather change, and 阅读全文
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``` You are given three integers a, b and x. Your task is to construct a binary string s of length n=a+b such that there are exactly a zeroes, exactly 阅读全文
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A sequence a1,a2,…,an is called good if, for each element ai, there exists an element aj (i≠j) such that ai+aj is a power of two (that is, 2d for some 阅读全文
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You are given two strings s and t. In a single move, you can choose any of two strings and delete the first (that is, the leftmost) character. After a 阅读全文
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Little girl Tanya climbs the stairs inside a multi storey building. Every time Tanya climbs a stairway, she starts counting steps from 1 to the number 阅读全文
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Maxim wants to buy some games at the local game shop. There are n games in the shop, the i th game costs ci. Maxim has a wallet which can be represent 阅读全文