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!
Array Stack Two Pointers
public int trap(int[] A) { int maxIndex = 0; for(int i=1; i<A.length; i++) { if(A[i] > A[maxIndex]) maxIndex = i; } int sum = 0; //from left to top int currentMax = 0; for(int i=1; i<maxIndex; i++) { if(A[i] < A[currentMax]) sum += (A[currentMax] - A[i]); else currentMax = i; } //from right to top currentMax = A.length-1; for(int i=A.length-2; i>maxIndex; i--) { if(A[i] < A[currentMax]) sum += (A[currentMax] - A[i]); else currentMax = i; } return sum; }
LeetCode-42 Trapping Rain Water
标签：
原文地址：http://www.cnblogs.com/linxiong/p/4294777.html
