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摘要： 题目描述 Given a string containing just the characters'(',')','{','}','['and']', determine if the input string is valid. The brackets must close in the co 阅读全文

摘要： 题目描述 Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it is able to trap after rai 阅读全文