盛最多水的容器

Problem description

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

Examples

Example 1:
Input: [1,8,6,2,5,4,8,3,7]
Output: 49

Solution

　　自己起初想以双指针从两头向中间逼近。但困惑于low、high的指针移动。我知道面积取决与最短板的长度。但是也还有宽度不是……..然后用了双层遍历，做是做出来了，但是特别耗时。参考网上代码，与我起初想法一致，向中间逼近，在指针移动时，采取移动最短指针，尽管面积 = 长度 * 宽度，但是面积取决于最短板，而且在移动过程中我们维护一个最大面积变量记录最大面积。可将宽度考虑其中。

Code

 public int maxArea(int[] height) {
    int maxArea = Integer.MIN_VALUE;
    int low = 0, high = height.length - 1;
    while (low < high) {
        int area = Math.min(height[low], height[high]) * (high - low);
        maxArea = Math.max(area, maxArea);
        if (height[low] <= height[high]) {
            low++;
        } else {
            high--;
        }
    }
    return maxArea;
}