Container With Most Water

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

Example:

Given [1,3,2], the max area of the container is 2.

Solution:

Two pointers, one start from left and one start from right. Find the maximum with Math.abs(h[left] - h[right])*(right - left).

Code:

public class Solution {
    /**
     * @param heights: an array of integers
     * @return: an integer
     */
    public int maxArea(int[] heights) {
        if (heights == null || heights.length < 2) {
            return 0;
        }
        int left = 0;
        int right = heights.length - 1;
        int max = 0;
        while (left < right) {
            max = Math.max( max, (right - left) * Math.min(heights[left], heights[right]));
            if(heights[left] < heights[right]){
                left++;
            } else {
                right--;
            }
        }
        return max;
    }
}