Container With Most Water | Leetcode solution in JavaScript

December 5, 2021 — #Leetcode

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.

for more details about the problem click here

Solution using Brute Force

It might gives an error which is TLE(Time Limit Exceeded)

Time complexity: O(n^2)
Space complexity: O(1)

var maxArea = function (height) {
  let area = 0;

  for (let i = 0; i < height.length; i++) {
    for (let j = i + 1; j < height.length; j++) {
      let newArea = min(height[i], height[j]) * (j - i);
      if (newArea > area) {
        area = newArea;
      }
    }
  }
  return area;
};

var min = function (i, j) {
  if (i < j) {
    return i;
  }
  return j;
};

Solution using Two pointer

Time complexity: O(n)
Space complexity: O(1)

var maxArea = function (height) {
  let low = 0;
  let high = height.length - 1;
  var area = 0;

  while (low < high) {
    const currArea = (height[low] > height[high] ? height[high] : height[low]) * (high - low);
    area = area < currArea ? currArea : area;

    if (height[low] > height[high]) {
      --high;
    } else {
      ++low;
    }
  }
  return area;
};