Container With Most Water

题目：

Given n non-negative integers a₁, a₂, ..., a_n, where each represents a point at coordinate (i, a_i). n vertical lines are drawn such that the two endpoints of line i is at (i, a_i) and (i, 0). Find two lines, which together with x-axis forms a container, such that the container contains the most water.

Note: You may not slant the container.

题解：

这道题是先从两头开始算面积，面积的计算要由短板决定，并维护一个当前最大面积。

替换小的短板来计算面积。每一步只替换短板的原因是，短板决定面积，而高板不影响。

 1     public int maxArea(int[] height) 
 2     {
 3         if(height==null||height.length==0) return 0;
 4         int low=0;
 5         int high=height.length-1;
 6         int max=0;
 7         int area=0;
 8         while(low<high)
 9         {
10             area=(high-low)*Math.min(height[low],height[high]);
11             max=Math.max(max,area);
12             if(height[low]<height[high]) low++;
13             else high--;
14             
15         }
16         
17         return max;
18         
19     }