[LintCode] Container With Most Water 装最多水的容器

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.

 Notice

You may not slant the container.

Have you met this question in a real interview? 

Yes

Example

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

LeetCode上的原题，请参见我之前的博客Container With Most Water。

解法一：

class Solution {
public:
    /**
     * @param heights: a vector of integers
     * @return: an integer
     */
    int maxArea(vector<int> &heights) {
        int res = 0, i = 0, j = heights.size() - 1;
        while (i < j) {
            res = max(res, min(heights[i], heights[j]) * (j - i));
            heights[i] < heights[j] ? ++i : --j;
        }
        return res;
    }
};

解法二：

class Solution {
public:
    /**
     * @param heights: a vector of integers
     * @return: an integer
     */
    int maxArea(vector<int> &heights) {
        int res = 0, i = 0, j = heights.size() - 1;
        while (i < j) {
            int h = min(heights[i], heights[j]);
            res = max(res, h * (j - i));
            while (i < j && h == heights[i]) ++i;
            while (i < j && h == heights[j]) --j;
        }
        return res;
    }
};