[Request] Add Nearest Greater and Smaller Element Algorithms

[adiancodes]

What would you like to Propose?

Proposal: Add a new file containing a set of classic stack-based algorithms.

Algorithm Name and Problem Statement:
I propose adding a new file, NearestElement.java, to the datastructures/stacks package. This file will implement four closely related algorithms:

1. Nearest Greater to Right: For each element in an array, find the first element to its right that is greater.
2. Nearest Greater to Left: For each element in an array, find the first element to its left that is greater.
3. Nearest Smaller to Right: For each element in an array, find the first element to its right that is smaller.
4. Nearest Smaller to Left: For each element in an array, find the first element to its left that is smaller.

Justification:
These algorithms are a fundamental application of the Stack data structure. They are highly valuable for educational purposes and are common in technical interviews and for solving many popular LeetCode problems.

Hacktoberfest Contribution:
I would like to work on this for Hacktoberfest. I have read the CONTRIBUTING.md guidelines and will ensure my submission includes a main method for demonstration and a full suite of JUnit 5 tests.

Issue details

Is your feature request related to a problem? Please describe.
This request is to add a set of classic algorithms that are excellent demonstrations of the Stack data structure. These are frequently asked in technical interviews and would be a valuable addition to the library. They are also fundamental for solving many popular LeetCode problems involving arrays and stacks.

Describe the solution you'd like
I would like to add a new file, NearestElement.java, inside the datastructures/stacks package. This file will contain four static methods:

• nearestGreaterToRight(int[] arr)
• nearestGreaterToLeft(int[] arr)
• nearestSmallerToRight(int[] arr)
• nearestSmallerToLeft(int[] arr)

Additional context
I would like to work on this contribution for Hacktoberfest.

I have read the CONTRIBUTING.md guidelines and will ensure my pull request includes:

1. A class-level Javadoc explaining the algorithms.
2. A main method inside NearestElement.java for demonstration.
3. A corresponding NearestElementTest.java file with JUnit 5 tests.

Could you please assign this issue to me?

Additional Information

No response

[shafaq16]

can you assign this issue to me

[sgindeed]

please check PR #6693

[RiyaJoshi0103]

Hi @alxkm,
I would like to work on this issue as part of Hacktoberfest 2025.
I’ll make sure to follow the contribution guidelines and write clean, well-documented Java code.
Thank you!

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contribution!