leetcode11 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 and n is at least 2.
The above vertical lines are represented by array [1,8,6,2,5,4,8,3,7]. In this case, the max area of water (blue section) the container can contain is 49.
Example:
Input: [1,8,6,2,5,4,8,3,7]
Output: 49
"""
"""
解法一：暴力解法
对数据量大，超时
Time Limit Exceeded
"""
class Solution1:
    def maxArea(self, height):
        most_water = 0
        if len(height) < 2:
            return 0
        for i in range(len(height)-1):
            for j in range(i+1, len(height)):
                h = min(height[i], height[j])
                most_water = max(most_water, h*(j - i))
        return most_water

"""
解法二：双指针法
让i=0, j=len(height)-1,从而保证底最长
如果高nums[i] < nums[j]  i++
否则j--
当重合i == j 退出迭代
"""
class Solution2:
    def maxArea(self, height) -> int:
        most_water = 0
        if len(height) < 2:
            return 0
        i = 0
        j = len(height) - 1
        while i < j:
            h = min(height[i], height[j])
            most_water = max(most_water, h*(j-i))
            if height[i] < height[j]:
                i += 1
            else:
                j -= 1
        return most_water