CS
Algorithms
Problems Base course RU

Method

precomputation

Articles

GRA Algorithm A* Dijkstra with a hint of how far is left: the wave stretches towards the goal, and the path stays shortest. O((V + E) log V) 2 problems GRA Algorithm Contraction hierarchies A navigator's precomputation: contract unimportant crossroads into shortcuts and find the path with two waves going up. O((V + E′) log V) 1 problem STR Algorithm Boyer–Moore Compares from right to left and skips letters: on long patterns it reads only a small part of the text. O(n + m) 2 problems NUM Algorithm Gaussian elimination A linear system by elimination: the pivot, LU, conditioning, sparse matrices and fill-in. O(n³): about n³/3 multiplications for the forward pass 2 problems

Problems

How a Python list grows How much Horspool reads The year from the indiction A dictionary of typos Decoding from code lengths Queries over the tiers The density threshold The good suffix table The quadtree of a photo

Often together

graph 3 classic 3 in production 3 shortest path 2 heuristic 2 heap 2 weighted graph 2 maps and navigation 2 games 1 interviews 1 string matching 1 text editors 1

Written by Viacheslav Legostin. Everything is free; readers’ code is not stored.

Computer Science The algorithms catalogue Problems Base course Mathematics legost.in

The algorithms catalogue

Problems

SRT Searching and sorting

  1. Binary search
  2. Binary search on the answer
  3. Exponential search
  4. Interpolation search
  5. External sorting
  6. Heapsort
  7. Counting sort and radix sort

DS Data structures

  1. Dynamic array
  2. Hash table
  3. Cuckoo hashing
  4. Bloom filter
  5. Binary heap
  6. Binary search tree
  7. AVL tree
  8. B-tree
  9. Disjoint set union
  10. Fenwick tree

GRA Graphs

  1. Storing a graph
  2. Breadth-first search
  3. Depth-first search
  4. Bridges and articulation points
  5. Dijkstra's algorithm
  6. A*
  7. Bidirectional search
  8. The Bellman–Ford algorithm
  9. Floyd–Warshall algorithm
  10. Johnson's algorithm
  11. Contraction hierarchies
  12. Dinic's algorithm
  13. Graph colouring
  14. Bipartite matching
  15. Hungarian algorithm
  16. Eulerian path
  17. Heavy paths
  18. Centroid decomposition

STR Strings and text

  1. The Aho–Corasick algorithm
  2. Boyer–Moore
  3. The Burrows–Wheeler transform
  4. Edit distance
  5. BK-tree
  6. Huffman code

DP Dynamic programming

  1. Dynamic programming
  2. Interval DP
  3. Bitmask DP
  4. Digit DP
  5. Convex hull trick
  6. Knuth and divide-and-conquer optimisations

PAR Paradigms

  1. Greedy algorithms
  2. Backtracking
  3. Branch and bound
  4. Divide and conquer
  5. Closest pair of points

NUM Numbers and algebra

  1. Euclid's algorithm
  2. Fast exponentiation
  3. Chinese remainder theorem
  4. Big integers
  5. Fast Fourier transform
  6. Gaussian elimination

GEO Geometry

  1. Vectors and orientation
  2. Convex hull
  3. Delaunay triangulation and Voronoi diagram

NUM~ Numerical methods

  1. Bisection and Newton's method
  2. Gradient descent

SYS Systems and big data

  1. Consistent hashing
  2. Count-Min Sketch
  3. HyperLogLog
  4. Inverted index and BM25
  5. Retry with jitter
  6. CRDT

ML Data and machine learning

  1. k-means
  2. DBSCAN
  3. Decision tree
  4. Perceptron and backpropagation

RND Randomness

  1. Genetic algorithm

TEC Techniques

  1. Big O
  2. Fast input and output
  3. How to benchmark honestly
  4. Cache-friendly data
  5. Complexity from measurements
  6. Amortized analysis
  7. Choosing a data structure
  8. Coordinate compression
  9. Bit tricks