Trapping Water

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

You are given an integer array height of length n. There are n vertical lines drawn such that the two endpoints of the ith line are (i, 0) and (i, height[i]).

Find two lines that together with the x-axis form a container, such that the container contains the most water.

Return the maximum amount of water a container can store.

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

Constraints:

  • n == height.length
  • 2 <= n <= 105
  • 0 <= height[i] <= 104
				
					const height = [8, 2, 4, 5, 1, 1];
const maxArea = (height: number[]) => {
  let i = 0;
  let j = height.length - 1;
  let width = 0;
  let minHeight = 0;
  let area = 0;
  let maxArea = 0;
  while (i <= j) {
    width = j - i;
    if (height[i] > height[j]) {
      minHeight = height[j];
      area = width * minHeight;
      if (area > maxArea) {
        maxArea = area;
      }
      j--;
    } else {
      minHeight = height[i];
      area = width * minHeight;
      if (area > maxArea) {
        maxArea = area;
      }
      i++;
    }
  }
  return maxArea;
};
console.log(maxArea(height));

Container With Most Water

Submission Detail

60 / 60 test cases passed.
Status: 

Accepted

Runtime: 109 ms
Memory Usage: 51.5 MB
Submitted: 3 months ago

https://leetcode.com/problems/trapping-rain-water/

Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it can trap after raining.

Example 1:

Input: height = [0,1,0,2,1,0,1,3,2,1,2,1]
Output: 6
Explanation: The above elevation map (black section) is represented by array [0,1,0,2,1,0,1,3,2,1,2,1]. In this case, 6 units of rain water (blue section) are being trapped.

Example 2:

Input: height = [4,2,0,3,2,5]
Output: 9

Constraints:

  • n == height.length
  • 1 <= n <= 2 * 104
  • 0 <= height[i] <= 105
				
					const height = [4, 0, 1, 5, 0, 0, 1];
const trap = (height: number[]) => {
  let leftmax = 0;
  let rightmax = 0;
  let waterLoggedUnit = 0;
  let i = 0;
  let j = height.length - 1;
  while (i < j) {
    if (height[i] < height[j]) {
      if (height[i] > leftmax) {
        leftmax = height[i];
        i++;
      } else {
        waterLoggedUnit += leftmax - height[i];
        i++;
      }
    } else {
      if (height[j] > rightmax) {
        rightmax = height[j];
        j--;
      } else {
        waterLoggedUnit += rightmax - height[j];
        j--;
      }
    }
  }
  return waterLoggedUnit;
};
console.log(trap(height));

Trapping Rain Water

Submission Detail

321 / 321 test cases passed.
Status: 

Accepted

Runtime: 102 ms
Memory Usage: 46.2 MB
Submitted: 3 months ago

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