Added the retrieval of minimum and maximum element from stack at O(1)

[S-M-J-I]

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• This pull request is all my own work -- I have not plagiarized it.
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[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 67.08%. Comparing base (87030af) to head (88c78f2).
Report is 1 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #5714      +/-   ##
============================================
+ Coverage     67.01%   67.08%   +0.07%     
- Complexity     4539     4556      +17     
============================================
  Files           616      618       +2     
  Lines         17043    17085      +42     
  Branches       3290     3294       +4     
============================================
+ Hits          11421    11462      +41     
  Misses         5167     5167              
- Partials        455      456       +1     

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[saahil-mahato]

This is missing test case when the maxStack is empty and we attempt to push or pop. Please confirm. Thanks.

[S-M-J-I]

This is missing test case when the maxStack is empty and we attempt to push or pop. Please confirm. Thanks.

Hi. Thanks for the comment. The test case when maxStack is empty and we attempt to pop from it is present as testBlankHandle(). The test case when the maxStack is empty and we attempt to getMaximum() from it is present as testNullMax(). As for the push, the maxStack will not be empty as long as the mainStack has at least one value. Thank you for bringing this to my attention, I will add a test case where we clear the stack and then try to push into it and try to retrive the max value.

[siriak]

We do not add leetcode problems, please add references to other sources if they exist

[S-M-J-I]

We do not add leetcode problems, please add references to other sources if they exist

Hello @siriak, I added another ref for this algorithm.

[S-M-J-I]

Hello @siriak, I have made the reference changes as advised. Please let me know your reviews.