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