For my last technical interview, I was asked about how to trap rainwater. (Not really 🤪). It was a hard level Leetcode problem. I found it challenging, that’s why I’d like to write a blog about it. To make sure I understand the approach to solve similar problems in the future.

Problem:

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

The above elevation map 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:

Input: [0,1,0,2,1,0,1,3,2,1,2,1]
Output: 6

#raindrop #leetcode #javascript #trapping-rain-water #programming