Problem name: Container With Most Water

Problem statement:

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

Constraints:

• n = height.length
• 2 <= n <= 3 * 104
• 0 <= height[i] <= 3 * 104

Solution: A simple solution with o(n) time complexity and o(1) space complexity.

class Solution {
public:
    int maxArea(vector<int>& height) {
        int start = 0;
        int end = height.size() - 1;
        int finalresult = 0;
        
        while(start != end){
            // minimum of length
            int length = height[start] > height[end] ?height[end]  :  height[start] ;
            int width = (end - start);
            int area = length * width;
            // taking max of area
            finalresult = area > finalresult ? area : finalresult ;
            
            if( height[start] < height[end]){
                start++;
            }
            else end--;
        }
        return finalresult;
    }
};