Here is the list of some of the good tutorials written by codeforces users :-
- DP on Trees by darkshadows
- Algorithm Gym :: Data Structures by PrinceOfPersia
- Everything about Segment Trees by PrinceOfPersia
- SOS DP by usaxena95
- Invariants and monovariants by TooNewbie
- Z algorithm by paladin8
- Mobius Inversion by Nisiyama_Suzune
- Dirichlet convolution by Nisiyama_Suzune
- C++ Tricks by HosseinYousefi
- Suffix Automata by quasisphere
- Fast convolution for 64-bit integers by quasisphere
- Tutorial for FFT/NTT Part 1 by sidhant
- Tutorial for FFT/NTT Part 2 by sidhant
If you know some good tutorial on codeforces which is not in this list please mention it in the comments I will add it in the list.