标签：
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.
The above elevation map is represented by array [0,1,0,2,1,0,1,3,2,1,2,1]. In this case, 6 units of rain water (blue section) are being trapped. Thanks Marcos for contributing this image!
思路：
1.先把最左边的0去掉；
2.挨个遍历每个柱子。
3.去重的处理
代码：
class Solution{ public: int trap(int A[], int n) { if(A==NULL||n==0) return 0; int i; int res=0; for(i=0;i<n;++i){ if(A[i]!=0) break; } int start=i+1; map<int,bool> repeatNum; while (start<n) { if(repeatNum.count(start)){++start;continue;} int l;int r; for(l=start-1;l>=0;--l){ if(A[l]>A[start]){ break; } } for (r=start+1;r<n;++r) { if(A[r]==A[start]) repeatNum[r]=true; if(A[r]>A[start]){ break; } } if(l==-1||r==n){ ++start;continue; } int temp=(min(A[l],A[r])-A[start])*(r-l-1); res+=temp; ++start; } return res; } };
标签：
原文地址：http://www.cnblogs.com/fightformylife/p/4227515.html
