# 11. Container with Most Water > [!META]- Inline Metadata > [tags:: #career #concepts/programming/algorithms/two-pointers ] > [project group:: Neetcode 150] > [difficulty:: medium] > [status:: done] > [link:: https://leetcode.com/problems/container-with-most-water/] > [up:: [[Leetcode MOC]]] ## 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 ![](https://s3-lc-upload.s3.amazonaws.com/uploads/2018/07/17/question_11.jpg) **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` ## Solution ### Mine Start with brute force: two pointers, go through every combo of left and right indices and keep the biggest area. $O(n^2)$ Improvements: - Start with right pointer at end of array - Change rule for shifting pointers: shift only the pointer from the smallest height. - If heights are equal, shift either one - When pointers are equal, end #### Python ```python def most_water(container: List[int]) -> int: max_area = 0 i = 0 j = len(container) - 1 while i != j: max_area = max(max_area, min(container[i], container[j]) * (j - i)) if container[i] < container[j]: i += 1 else: j -= 1 return max_area ``` #### Rust ### LC's ## Things I Learned ## Scratchpad