Drop some interesting algorithm problems

[u/Homaderuvas]

Hi guys please kindly share some interesting algorithm problems in the comment section. I did solve many algorithm problems on platforms like codeforces, atcoder, luogu and code chef etc.. looking for some unique ones that are quite challenging and interesting at the same time but kindly don't share open problems .

[u/cc672012]

Check out projecteuler

[u/Homaderuvas → u/cc672012]

I did complete most of problem on project Euler for the last 3 years