Container With Most Water 解答

Question

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.

Solution

Since the area size is largely depended on shorter height, so we use two pointers. Time complexity O(n), space cost O(1).

public class Solution {
    public int maxArea(int[] height) {
        if (height == null || height.length < 2)
            return 0;
        int left = 0, right = height.length - 1;
        int result = 0, tmp = 0;
        while (left < right) {
            tmp = (right - left) * Math.min(height[left], height[right]);
            result = Math.max(result, tmp);
            if (height[left] <= height[right])
                left++;
            else
                right--;
        }
        return result;
    }
}