【LeetCode】Trapping Rain Water 2013年美团网校园招聘研发工程师笔试题
Given n non-negativeintegersrepresentinganelevationmapwherethewidthofeachbaris1,computehowmuchwateritisabletotrapafterraining.Forexample, Given [0,1,0,2,1,0,1,3,2,1,2,1],return 6.Theaboveelevationmapi