LeetCode 11 Container with Most Water 解题思路和python代码

题目：

You are given an integer array height of length n. There are n vertical lines drawn such that the two endpoints of the ith line are (i, 0) and (i, height[i]).

Find two lines that together with the x-axis form a container, such that the container contains the most water.

Return the maximum amount of water a container can store.

Notice that you may not slant the container.

Example 1:

Input: height = [1,8,6,2,5,4,8,3,7]

Output: 49

Explanation: 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 2:

Input: height = [1,1]

Output: 1

Constraints:

n == height.length

2 <= n <= 105

0 <= height[i] <= 104

解题思路：

我们可以看到这里水的体积多少取决于两边的竖直线中较短的那一条。我们可以使用两个指针，一个指向数组的第一个数，另一个指向数组的第二个数。我们可以计算面积，同时移动两个指针中，指向较短竖直线的那一个。

class Solution:
    def maxArea(self, height: List[int]) -> int:
        left = 0
        right = len(height) - 1
        max_area = 0
        
        while left < right:
        	# Calculate the current area 
            width = right - left
            current_area = min(height[left], height[right]) * width

			# Update max_area if the current one is larger
            max_area = max(max_area, current_area)

			# Move the pointer that points to the shorter line
            if height[left] < height[right]:
                left += 1
            else:
                right -= 1
        return max_area
        

Time Complexity 是 O(n)

Space Complexity 是 O(1)