Trapping Rain Water Problem in C++

[abhagangwar712]

Please let me contribute this issue under hactoberfest.

Problem Description:
The Trapping Rainwater problem involves calculating the amount of water that can be trapped after a rainstorm given a list of non-negative integers representing the elevation map. The width of each bar is 1. The goal is to find the maximum amount of water that can be trapped.

Optimized Approach using Two Pointers (O(n) time complexity):

Use two pointers to traverse the elevation map from both ends.
Track the maximum heights seen so far from both sides.
Calculate the water trapped based on the minimum of these heights.

[mihir-k64]

Pls assign me this under hacktober