Container with most water

ID: 11

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 the line i is at (i, ai) and (i, 0). Find two lines, which, together with the x-axis forms a container, such that the container contains the most water.

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.

Idea

Two pointers

left=0, right=length-1;

getArea for each left--right pair, left++ if height[left]<height[right], otherwise right++

Code

public int maxArea(int[] height) {
        int left = 0;
        int right = height.length-1;
        
        int max = 0;
        while(left<right){
            if(getArea(height, left, right)>max){
                max = getArea(height, left, right);    
            }
            if(height[left]<height[right]){
                left++;
            }
            else{
                right--;
            }
        }
        
        return max;
    }
    
    private int getArea(int[] height, int left, int right){
        int h = height[left]<height[right]?height[left]:height[right];
        int w = right-left;
        return h*w;
    }