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 raining. For example, Given [0,1,0,2,1,0,1,3,2,1,2,1], return 6. 解题思路: 先找到第一块最高的木板,然后从前向最高木板遍历,接着从后向最高木板遍历,J…