Container With Most Water

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.

Note: You may not slant the container.

左右两个指针夹逼准则。如果left < right，先记录当前area，left++，反之则right--。因为如果left小的话，如果我们移右指针，结果总比当前area小。

public class Solution {
    //Time: O(n)  Space: O(1)
    public int maxArea(int[] height) {
        if (height == null || height.length <= 1) {
            return 0;
        }
        
        int left = 0;
        int right = height.length - 1;
        int area = 0;
        while (left < right) {
            int h = Math.min(height[left], height[right]);
            area = Math.max(area, h * (right - left));
            if (height[left] == h) {
                left++;
            } else {
                right--;
            }
        }
        return area;
    }
}