Request to Contribute: Number Theory and Modular Arithmetic Helpers for CP

[Subhankar-Ray192]

Hello Maintainers,

I've been using this repository as part of my competitive programming workflow and have found it very helpful. I would like to ask if you are open to contributions focused on number theory and modular arithmetic utilities—tools that are commonly used in competitive programming but are not readily available or standardized in the Python ecosystem.

Proposed Contributions

If this direction aligns with the goals of the project, I would like to implement the following utilities step-by-step. Each would include clean and well-documented implementations, example usage, and optional test cases:

• ModInt wrapper class for safe and consistent modular arithmetic (similar to C++'s modint)
• Modular inverse functions using both Fermat’s Little Theorem and the Extended Euclidean Algorithm
• Efficient computation of binomial coefficients under modulo (nCr % mod)
• Sieve of Eratosthenes with smallest prime factor (SPF) support
• Miller-Rabin primality test (probabilistic, suitable for large inputs)
• Euler’s Totient Function and Möbius Function

The focus would be on clarity, reusability, and performance for CP-style applications.

If this proposal sounds useful, I would be happy to begin by submitting a pull request for the ModInt wrapper as a first step.

Thank you for your time and consideration. I look forward to your feedback.

Best regards,
Subhankar-Ray192

[Shikha-code36]

Hi, Thankyou for all the suggestions. You suggestion sounds interesting and you have listed down reasons as well. Please go ahead and create PR. Please make sure it doesn't effect the existing functioning of the code. Regards, Shikha Pandey

…

On Wed, 16 Jul, 2025, 5:17 pm Subhankar Ray, ***@***.***> wrote: *Subhankar-Ray192* created an issue (Shikha-code36/Competitive-Python#5) <#5> Hello Maintainers, I've been using this repository as part of my competitive programming workflow and have found it very helpful. I would like to ask if you are open to contributions focused on number theory and modular arithmetic utilities—tools that are commonly used in competitive programming but are not readily available or standardized in the Python ecosystem. *Proposed Contributions* If this direction aligns with the goals of the project, I would like to implement the following utilities step-by-step. Each would include clean and well-documented implementations, example usage, and optional test cases: - ModInt wrapper class for safe and consistent modular arithmetic (similar to C++'s modint) - Modular inverse functions using both Fermat’s Little Theorem and the Extended Euclidean Algorithm - Efficient computation of binomial coefficients under modulo (nCr % mod) - Sieve of Eratosthenes with smallest prime factor (SPF) support - Miller-Rabin primality test (probabilistic, suitable for large inputs) - Euler’s Totient Function and Möbius Function The focus would be on clarity, reusability, and performance for CP-style applications. If this proposal sounds useful, I would be happy to begin by submitting a pull request for the ModInt wrapper as a first step. Thank you for your time and consideration. I look forward to your feedback. Best regards, Subhankar-Ray192 — Reply to this email directly, view it on GitHub <#5>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AULGCKJHVFAVD7CXCVSY3ET3IY3V7AVCNFSM6AAAAACBUVG5EGVHI2DSMVQWIX3LMV43ASLTON2WKOZTGIZTKNRTGYZTCMI> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[Subhankar-Ray192]

Thank you for the opportunity. I'll make sure the changes do not affect existing functionality and will raise the PR shortly. Looking forward to your feedback.

Regards,
Subhankar-Ray192

Hi,

Thankyou for all the suggestions.

You suggestion sounds interesting and you have listed down reasons as well.

Please go ahead and create PR.
Please make sure it doesn't effect the existing functioning of the code.

Regards,
Shikha Pandey
…

[Shikha-code36]

thanks