I'm just in a mood to shitpost. Don't take it too seriously.
Things that I have heard of, but don't know (imagine how many things I haven't even heard of):
- Li-Chao Segment Tree
- Segment Tree Beats
- RMQ in $$$O(n)$$$/$$$O(1)$$$
- Any self-balancing tree except treap
- Link-cut tree
- Wavelet tree
- Mergesort tree
- Binomial heap
- Fibonacci heap
- Leftist heap
- Dominator tree
- 3-connected components in $$$O(n)$$$
- $$$k$$$-th shortest path
- Matching in general graph
- Weighted matching in general graph
- Preflow-push
- MCMF in $$$O(poly(V, E))$$$
- Minimum arborescence (directed MST) in $$$O(E \log V)$$$
- Suffix tree
- Online convex hull in 2D
- Convex hull in 3D
- Halfplane intersection
- Voronoi diagram / Delaunay triangulation
- Operation on formal power series (exp, log, sqrt, ...) (I know the general idea of Newton method)
- How to actually use generating functions to solve problems
- Lagrange Inversion formula
- That derivative magic by Elegia
- That new subset convolution derivative magic by Elegia
- How Elegia's mind works
- Sweepline Mo
- Matroid intersection
If you know at least 3 of these things and you are not red — you are doing it wrong. Stop learning useless algorithms, go and solve some problems, learn how to use binary search.