11. Container With Most Water

LeetCode problem

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

First accepted

Idea:

• Two Pointers

1. Max water area is limited by the height of the shorter line
2. Get most left pointer and most right
3. Loop until left==right

class Solution:
    def maxArea(self, height: List[int]) -> int:
        p1 = 0 # indexes
        p2 = len(height) - 1

        max_water = 0
        while p1 < p2:
            area = (p2 - p1) * min(height[p1], height[p2])
            max_water = max(area, max_water)

            if height[p1] <= height[p2]:
                p1 += 1
            else:
                p2 -= 1
        return max_water