ContainerWithMostWater.java

/**
 * Container With Most Water http://oj.leetcode.com/problems/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.
 * 
 * Note: You may not slant the container.
 * 
 * @author Josh Luo
 * 
 *         This problem is very interesting. You need to think through that the smaller height is actually the
 *         bottle-neck of that area, so you have to move the smaller height forward.
 */

public class ContainerWithMostWater {
    public int maxArea(int[] height) {
        // IMPORTANT: Please reset any member data you declared, as
        // the same Solution instance will be reused for each test case.
        assert (height != null);
        int i = 0, j = height.length - 1, maxArea = 0;
        while (i < j) {
            int area = 0;
            if (height[i] < height[j]) {
                area = height[i] * (j - i);
                i++;
            } else {
                area = height[j] * (j - i);
                j--;
            }
            maxArea = Math.max(maxArea, area);
        }
        return maxArea;
    }
}