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题目：Givennpairs of parentheses, write a function to generate all combinations of well-formed parentheses.For example, givenn= 3, a solution set is:"(((... 阅读全文
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题目：Say you have an array for which theithelement is the price of a given stock on dayi.If you were only permitted to complete at most one transaction ... 阅读全文
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题目：A robot is located at the top-left corner of amxngrid (marked 'Start' in the diagram below).The robot can only move either down or right at any poi... 阅读全文