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The highest building in our city has only one elevator. A request list is made up with N positive numbers. The numbers denote at which floors the elev 阅读全文
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Look-and-say sequence is a sequence of integers as the following: D, D1, D111, D113, D11231, D112213111, ... where D is in [0, 9] except 1. The (n+1)s 阅读全文
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The basic task is simple: given N real numbers, you are supposed to calculate their average. But what makes it complicated is that some of the input n 阅读全文
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Scientific notation is the way that scientists easily handle very large numbers or very small numbers. The notation matches the regular expression [+- 阅读全文
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People often have a preference among synonyms of the same word. For example, some may prefer "the police", while others may prefer "the cops". Analyzi 阅读全文
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#include <iostream> #include <regex> using namespace std; int main() { string str; getline(cin,str); for(int i=0;i<str.length();i++) str[i]=tolower(st 阅读全文
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A Digital Library contains millions of books, stored according to their titles, authors, key words of their abstracts, publishers, and published years 阅读全文