PSA and PDA
Binary search
Bitwise operations
BFS and DFS
Dijkstra's, Prim's, SPFA
Disjoint union
Greedy
Dynamic programming
Linear algebra and matrix exponentiation
Computational geometry
Polygons
Convex hull
Line sweep
Segment trees with lazy propagation
Binary indexed trees
Binary search trees (mostly splay)
Tarjan's SCC
Heavy-light decomposition
Maximum flow and bipartite matching
Hashing