skip to primary navigationskip to content

Department of Computer Science and Technology

Randomised Algorithms

Course pages 2021–22

Randomised Algorithms

Lecture Slides

  • Lecture 1 (Introduction) PDF
  • Lecture 2-3 (Concentration Inequalities and Chernoff Bounds) PDF
  • References: Mitzenmacher, Upfal (Chapter 4)
  • Lecture 4 (Markov Chains and Mixing Times) PDF
  • References: Mitzenmacher, Upfal (Chapter 7, 11)
  • Lecture 5 (Random Walks, Hitting Times and A Randomised Algorithm for 2-SAT) PDF
  • References: Mitzenmacher, Upfal (Chapter 11); Levin, Wilmer, Peres
  • Lecture 6-7 (Linear Programming and the Simplex Algorithm) PDF
  • References: Cormen, Leiserson, Rivest, Stein (Chapter 29)
  • Lecture 8 will be an interactive demo of how to solve a TSP instance using Linear Programming
  • Lecture 9-10 (Randomised Approximation Algorithms) PDF
  • References: Cormen, Leiserson, Rivest, Stein (Chapter 35)
  • Lecture 11-12 (Spectral Graph Theory and Clustering) PDF
  • References: Trevisan ``Lecture Notes on Graph Partitioning, Expanders and Spectral Methods'' PDF
  • Lecture 13 (Streaming Algorithms) PDF
  • References: Muthurkishnan ``Data Streams: Algorithms and Applications'' PDF
  • Lecture 14 (Online Learning with Experts) PDF
  • References: Understanding Machine Learning: From Theory to Algorithms (Chapter 21), Cambridge University Press
  • Lecture 15 (Multi-Armed Bandits) PDF
  • References: Lattimore, Szepesvari ``Bandit Algorithms'', Cambridge University Press PDF

Some of the animations (Lecture 5 and Lecture 11-12) may require a special PDF reader like Adobe Acrobat Reader.

If you have any questions or found errors in the slides / videos / exercise questions, please email me: [Javascript required]

Handout (compressed version of slides without lengthy animations)

  • Lecture 1 (Introduction) PDF
  • Lecture 2-3 (Concentration Inequalities and Chernoff Bounds) PDF
  • Lecture 4 (Markov Chains and Mixing Times) PDF
  • Lecture 5 (Random Walks, Hitting Times and A Randomised Algorithm for 2-SAT) PDF
  • Lecture 6-7 (Linear Programming and the Simplex Algorithm) PDF
  • Lecture 9-10 (Randomised Approximation Algorithms) PDF
  • Lecture 11-12 (Spectral Graph Theory and Clustering) PDF
  • Lecture 13 (Streaming Algorithms) PDF
  • Lecture 14 (Online Learning with Experts) PDF
  • Lecture 15 (Multi-Armed Bandits) PDF
  • Corrections

    • 25. January: Lecture 4, slide 11: fixed definition of periodicity
    • 27. January: Lecture 2/3, slide 30: fixed Quick-Sort Example (in the tree, there was a redundant node with a single "1", and thus the sum of comparison formula was also wrong).
    • 23. February: Lecture 13, slide 15: It was wrongly claimed that with probability 1/2^r, we have rho(h(x))=r. Instead, it should be with probability 1/2^r, we have rho(h(x))>=r. Many thanks to Nav Leelarathna.
    • 11. March: Lecture 15. Several minor typos fixed and explanations added.
    • 5. April: Lecture 14, slide 19, 20 and 22: The factor sqrt(2) in the mistake bound should instead be 2. Many thanks to Nav Leelarathna.

    References

    1. Cormen, T.H., Leiserson, C.D., Rivest, R.L. and Stein, C. (2009). Introduction to Algorithms. MIT Press (3rd ed.). ISBN 978-0-262-53305-8
    2. David P. Williamson and David B. Shmoys. The Design of Approximation Algorithms, Cambridge University Press, 2011 PDF
    3. Michael Mitzenmacher and Eli Upfal. Probability and Computing: Randomized Algorithms and Probabilistic Analysis. Cambridge University Press, 2nd edition.
    4. David Asher Levin, Elizabeth Wilmer, Yuval Peres. Markov Chains and Mixing Times. American Mathematical Society, 2009 PDF

    Exercise Questions

    • PDF
    • The questions discussed in the example classes are highlighted.

    Example Classes

    • Example Class 1 (3 February) Slides PDF or Handout PDF
    • Exercise Questions: L1 Q1, L2/3 Q2,5 and 7.
    • Example Class 2 (10 February) Handout PDF
    • Exercise Questions: L4/5 Q2,4,6,12 and 14.
    • Example Class 3 (17 February) Slides PDF or Handout PDF
    • Demo on how we can use Linear Programming in order to solve an instance of the Travelling Salesman Problem
      Link to the Program including Data Set and Visualisation: Link
      Reference to the Article fom 1954: Dantzig, G., Fulkerson, R. and Johnson, S. (1954) Solution of a Large-Scale Traveling-Salesman Problem. Journal of the Operations Research Society of America, 2, 393- 410. Link
    • Example Class 4 (24 February) Handout PDF
    • Exercise Questions: L6/7 Q3,4 L9/10 Q2,5, L11/12 Q6
    • Example Class 5 (10 March) Handout PDF
    • Exercise Questions: L11/12 Q5, L13 Q1, L14 Q1, Q3, Q4
    • All example classes will be recorded.

    Instructions for lecturers: how to edit this page