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!
public class Solution {
public int trap(int[] A) {
int result = 0,temp;
int []leftmax=new int [A.length];
int []rightmax=new int [A.length];
for(int i=0,max=-1;i<A.length;i++){
leftmax[i]=max;
max=max>A[i]? max:A[i];
}
for(int i=A.length-1,max=-1;0<=i;i--){
rightmax[i]=max;
max=max>A[i]? max:A[i];
}
for(int i=1;i<A.length-1;i++){
temp=Math.min(leftmax[i], rightmax[i]);
if(temp>A[i]){
result+=temp-A[i];
}
}
return result;
}
}LeetCode 41 Trapping Rain Water
原文地址：http://blog.csdn.net/mlweixiao/article/details/41483807
