11. Container With Most Water

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

Problem

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 the line i is at (i, ai) and (i, 0). Find two lines, which, together with the x-axis forms a container, such that the container contains the most water.

Notice that you may not slant the container.

Example 1:

Input: height = [1,8,6,2,5,4,8,3,7]
Output: 49
Explanation: 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.

Example 2:

Input: height = [1,1]
Output: 1

Example 3:

Input: height = [4,3,2,1,4]
Output: 16

Example 4:

Input: height = [1,2,1]
Output: 2

Constraints:

• 2 <= height.length <= 3 * 104

• 0 <= height[i] <= 3 * 104

Solution

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

• #twopointer