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.

典型的雙指針應用問題，令low = 0, high = len - 1,然後向中間靠攏，向中間靠攏意味着寬在減少，那爲了使面積更加得大，唯一的可能是找到更高的高度。

class Solution {
public:
    //雙指針
    int maxArea(vector<int>& height) {
        int len = height.size();
        if(len < 2)
            return 0;
        int low = 0, high = len - 1;
        int max = -1;
        while(low < high)
        {
            int tmpArea = (high - low) * min(height[low], height[high]);
            max = (max < tmpArea) ? tmpArea : max;
            if(height[low] <= height[high])
                ++low;
            else
                --high;
        }
        
        return max;
    }
};