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 and n is at least 2.

分析：

方法一：使用最簡單的嵌套循環遍歷，找出每一種組合。但此方法超時

方法二：容器的盛水量取決於兩塊板中的最短板，所以兩個指針，一頭一尾，記錄其盛水量，然後向中間移動其較短的板，期間記錄最大盛水量，直至兩個指針相遇。這樣時間復雜度就由方法一的O(N²)變為了O(N)。使用兩個指針，一頭一尾的方法很值得借鑒。

class Solution(object):
    def maxArea(self, height):
        """
        :type height: List[int]
        :rtype: int
        
 
"""
        n = len(height)
        i = 0
        j = n-1
        max_area = 0
        while(i<j):
            if height[i] < height[j]:
                area = (j-i)*height[i]
                i += 1
            else:
                area = (j-i)*height[j]
                j -= 1
            if area > max_area:
                max_area 
 
= area
        return max_area

Container With Most Water