Binary Indexed (Fenwick) Trees in C++

[cs-mshah]

Feature ✅

Description

Implementation of Fenwick trees to answer multiple queries on an array fast.

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• [*] I have read the project guidelines.
• [*] I have checked all the existing projects, before submitting a new project issue.
• [*] This issue will be meaningful for the project.
• [*] I will contribute more in future

[cs-mshah]

@pratik-choudhari can you assign this issue to me.

[Nishitk-20]

I can do this in java. Can you assign me.