Jul 31, 2023
Things I Do Not Know
I managed to survive for quite a long time in Competitive Programming without knowing or understanding a lot of things. Granted, many of the things I mentioned below are very niche during the time I still actively participate in CP contests. I am not saying that you should not learn any of this. If you are interested in learning something, just go for it. (though knowing too much might be detrimental...)
Anyway, I am just making this for fun. Might be updated if I came across new things.
Note: this post is inspired by this.
- Generating Function
- How FFT and any of its variations e.g FWHT works
- I only know they can be used to "multiply" polynomial
- Young tableaux
- Berlekamp-Massey algorithm
- Stirling numbers
- Simplex
- Mathematical formulation of
MorbiusMöbius inversion- I always think of Möbius inversion as a mathematical formulation of some inclusion-exclusion principle on GCD things
- Knuth-Morris-Pratt algorithm
- Though I understand how Aho-Corasick trie works
- How to build LCP in Suffix Array deterministically in
- I can imagine how to build it in randomized with hashing
- I do know how to use it
- Suffix tree
- Suffix automaton
- Z-algorithm
- Manacher algorithm
- Eertree
- Delaunay triangulation
- Voronoi diagram
- Minkowski sum
- Any 3D geometry things
- Slope trick DP
- Connected components DP
- "Aliens" DP
SOS DP- Kinda get the basic idea tho
- (10-08-2023) understood, basically just a generalization of "GCD/LCM" things that I already used a lot (note: while I am not sure what the correct terminology is, I think instead of SOS DP what I didn't understand before is "Zeta transformation")
- Knuth optimization
- I remember there is some quadrangle inequality, but that's it
- Li-Chao tree
- Segment tree beats
- Splay tree
- Link-cut tree
- Wavelet tree
- Top tree
- Matching in general graph (e.g Edmonds' blossom algorithm)
- Matroid intersection
- Directed MST (i.e minimum arborescence)
- Why Gomory-Hu tree is correct
- Kirchoff theorem
the only Kirchoff I know is the one in physics - Hungarian algorithm
- I think at some point I understood it, but not anymore
- Fraction binary search, i.e do binary search but output the answer in fraction form instead
of the decimal form (for example,
1/3
instead of0.333
).