Competition
Competitive programming in Algorithms e-maxx in english: https://cp-algorithms.com/
Source code of many know algorithm: https://github.com/indy256/codelibrary/tree/master
Suffix Arrays: https://web.stanford.edu/class/cs97si/suffix-array.pdf
COMPETIONS:
List Of Algos/Materials: https://codeforces.com/blog/entry/13529 https://github.com/hkirat/Algorithmic-Resources
Competitive programming handbook: https://cses.fi/book/book.pdf
Articles and Specific Topic: Zeta Transform, Mobius Transform and Subset Sum Convolution: Sum over Subsets(SOS) - https://codeforces.com/blog/entry/45223 Mobius Inclusion/Exclusion and Subset sum convolution - https://codeforces.com/blog/entry/72488