leetcode 11 Container With Most Water

原题：

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.

大意：

给你n条线，任意挑两条，求以这两条线的x坐标为长度，最短的那条线给高度的面积的最大值。

[code]class Solution
{
public:
    int maxArea(vector<int>& h)
    {
        int i=0,j=h.size()-1;
        int ans=-1;
        while(i<j)
        {
            ans=max(ans,min(h[i],h[j])*(j-i));
            if(h[i]<h[j])
                i++;
            else
                j--;
        }
        return ans;
    }
};

解答：

之前上来两个循环遍历，结果超时了= =

考虑动态规划，结果想不出来= =

考虑用hash记录，结果还是想不出来= =

由于没有用hash，二分也不可能。只能有o(n)的算法，可以我没想到= =

看别人的题解知道要从两端遍历，判断两端那条线短，短的那条线前进。记录结果即可