## Problem

Given *n* non-negative integers *a _{1}*,

*a*, …,

_{2}*a*, where each represents a point at coordinate (

_{n}*i*,

*a*).

_{i}*n*vertical lines are drawn such that the two endpoints of line

*i*is at (

*i*,

*a*) and (

_{i}*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.

## Analysis

We can use double pointers to solve this problem, let left and right denote the index of left and right pointer respectively, then we have

*– height[left] < height[right], left++*

*– height[left] >= height[right], right–*

## Solution

class Solution { public: int maxArea(vector<int>& height) { if(height.size()<=1) return 0; int left = 0; int right = height.size()-1; int max = 0; //two pointer while(left < right){ //compute size int curr = min(height[left], height[right]) * (right - left); if(max < curr) max = curr; if(height[left] < height[right]){ left++; }else{ right--; } } return max; } };