題目描述(Medium)

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 and n is at least 2.

The above vertical lines are represented by array [1,8,6,2,5,4,8,3,7]. In this case, the max area of water (blue section) the container can contain is 49.

題目連結

https://leetcode.com/problems/container-with-most-water/description/

Example 1:

Input: [1,8,6,2,5,4,8,3,7]
Output: 49

演算法分析

從頭尾往內部縮，容積取決於短板。

提交程式碼：

class Solution {
public:
    int maxArea(vector<int>& height) {
        int left = 0, right = height.size() - 1;
        int max_area = -1;
        
        while (left < right) {
            int area = min(height[left], height[right]) * (right - left);
            max_area = max(max_area, area);
            
            if (height[left] <= height[right])
                ++left;
            else
                --right;
        }
        
        return max_area;
        
    }
};