leetcode——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.

我以爲這是一個很是tricky的問題，若是你不懂得數學解法的話，這道題基本作不出來（窮舉法會超時）。而你知道了數學解法後，就以爲這道題很簡單。

class Solution {
public:
    int maxArea(vector<int>& height)
    {
        int n = (int)height.size();
        int left = 0;
        int right = n - 1;
        int max_volume = 0;

        while (left < right)
        {
            int x_ais = right - left;
            int y_ais = height[left] < height[right] ? height[left] : height[right];
            if (max_volume < x_ais * y_ais)
            {
                max_volume = x_ais * y_ais;
            }
            if (height[left] < height[right])
            {
                left++;
            }else{
                right--;
            }
        }

        return max_volume;
    }
};