[Code Addition Request]: [DSA: Stack] Add advanced stack-based problems (Rainwater Trapping, Asteroid Collision, Next Greater Element) to the repo #1580

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Guidelines

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• I have the link to my latest merged PR

Latest Merged PR Link

#1517

Project Description

I would like to contribute implementations (with explanations and test cases) of the following advanced stack problems:

Trapping Rain Water
LeetCode #42 – Using a monotonic stack or two-pointer approach.

Asteroid Collision
LeetCode #735 – Using stack simulation for handling collisions.

Next Greater Element (I & II)
LeetCode #496 and #503 – Efficient use of a monotonic stack.

These problems are frequently asked in tech interviews and help build intuition around stack questions.
Since I'm currently learning DSA, this will help me test my concepts better by writing quality code that is easy to understand for others also.

Full Name

Sneha Pandey

Participant Role

GSSOC Contributor