Course Policies


There will be two in-class midterms, and a final during the finals period. There will also be 7 homework assignments and a collection of short online quizzes. The 7 homework assignments contain some written assignments that you are to do on your own and some oral presentation assignments that you will do in groups of three.
4 Written Homeworks20% (5% each)
3 Oral Homeworks15% (5% each)
Online Quizzes+Class Participation+Bonus12% (see below)
Midterm exams (in class)30% (15% each)
Final exam23%


  • Everyone is expected to go to their recitation section. Recitations are a chance to engage in more discussion than is usually possible in a large lecture, with a focus on the process of solving algorithmic problems. Recitations will occasionally contain new material as well, on which you may be tested.


  • There will be two midterms and one final exam.
  • Midterms will be offered in class and will take the full class period. See the schedule for the exam dates.

Online Quizzes

  • There will an online quiz most weeks, for a total of 12 quizzes. Most quizzes will be due Friday 11:59pm; you can ask for help with them on Friday in recitations.
  • You will be tested on the material from the previous 2-3 lectures. You may refer to the course materials to solve the quizzes.
  • Quizzes are designed to make sure you are keeping up with the material presented in lectures. If you are, you will find most of the problems easy.

Online Quizzes+Class Participation+Bonus

  • 12% of your grade is allocated to "Online Quizzes + Class Participation+Bonus". This works as follows.
    • Quiz: Each quiz is worth 1 point. There are 12 quizzes.
    • Class Participation: The course staff will award 3 points for class participation, based on your participation in piazza, lectures, and recis. We have not decided on the exact breakdown here yet. We believe that attending lectures and recis, and participating in discussions on piazza are important parts of the course, since they allow you to learn. So we are giving you an incentive to do so.
      • Piazza: For piazza, we would be very happy if you answer fellow student questions without giving away solutions or hints to the homework problems.
      • Lecture Attendance: For lectures, in each lecture we may randomly decide to take a piazza poll where we will ask a question on piazza. You can use your cell phone to answer the question. You will not be graded on your answer to the question, but your response will be used to indicate that you are present at the lecture, and help us see if there are any confusing aspects of the lecture.
      • Recitations: We will get feedback from your TAs for attending and participating in recitation. It may help to stick to the same recitation so that your TA knows who you are.
    • Bonus Finally, we may occasionally give out bonus problems worth 1-2 points.
    • We total the points up from online quizzes, class participation, and bonus, and cap at 12.
  • E.g., one way to get 100% on this set of points is to get an average of 75% on the 12 quizzes, and get three points for class participation.


There will be written homeworks and oral presentations, described below.

Written HWs

  • Each written HW will have four (4) problems. One of these will a programming problem. (See the section on programming problems below for more details on these.) The other three problems will be written problems.
  • You should work on all problems in a written homework by yourself, unless explicitly told otherwise (we may give a few collaborative written problems this semester). If you have questions, come to office hours. Or, post on Piazza for clarification questions.
  • The written problems on these homeworks should be submitted electronically via gradescope. Homeworks will be due at 11:59PM on their due date.
  • You must typeset your homework. This makes your HWs legible, and the writing forces you to (re)think through the answers. Of course, merely typesetting your HW is no guarantee of legibility. Please re-read over your submissions! If we cannot understand what you've submitted, you may lose points.
  • LaTeX (see Miktex for Windows machines) is a good typesetting system for documents with math. Here's a LaTeX guide by Adam Blank, and a Latex template for Hwks. You can customize it as you like.
  • You will lose points for late submissions. Up to 24 hours late: 10 points off. 24-48 hours late: 20 points off. If you want to submit more than 48 hours late, you will lose 75 points. Moreover, you cannot submit electronically after 48 hours, and must contact your TA to submit. At this point solutions will be posted and you may look at them, though anything handed in should be put into your own words
  • Each student also gets 2 "grace/mercy days", aka "10% off off coupons". These will be automatically applied to counteract up to 20% total in lateness penalties. Not good on hwks turned in more than 48 hours late. Non-transferrable. Void where prohibited.
  • If you use any reference or webpage or material from any other class (including past iterations of 451), you must cite it, else it will be considered cheating. We reserve the right to deduct points for using such material beyond reason.

Oral HWs

  • Each oral homework (Homeworks 2,4, and 7) has four (4) problems. One of these will be a programming problem. The other three will be regular problems for oral presentations.
  • These homeworks are your chance for collaboration. Please form groups of three. The members of your group will work together to solve all four problems.
    • For the lone programming problem, you must then write the solution program by yourself! The submission process is the same as for the other homeworks.
    • For the three oral presentation problems, you will present your solutions, as a group, to one of the course staff. Presentations will be given in 45-minute time slots (there will be an electronic sign-up sheet reachable from the course home page). At the presentation, each member of the group will spend 15 minutes presenting one of the problems. The instructor/TA will decide who presents which problem, but when one member is presenting, other members are allowed to chime in too. In the end, the three presentations together will determine the score for the group. However, we reserve the right to give different members different scores when we believe it is warranted.
  • If you are nervous about your presentation, you may in addition hand in a written sketch of your solution as well. (This is optional.) We will then take this writeup into consideration in determining your grade on the assignment.

Programming Problems

  • The solutions to programming problems will be submitted via Autolab. Your program will read its input from standard input and output to standard output. It will be judged on correctness and running time. The languages accepted are Java, C, C++, Ocaml, SML. (Sorry, no Python this semester.) More details will appear on piazza.
  • For tips and further instructions on the programming problems, see here
  • Our submission system will run plagiarism-detection software on the submissions. Please do not copy!

Solving the Homework

Ideally, this is how you should approach the homework.
  1. Read the material taught in class, and make sure you understand all the definitions, algorithms, theorems and proofs.
  2. Read the homework problem. Carefully.
  3. If you get stuck, here are some suggestions to get past it:
    • Come up with a small example, and see how you would solve that. This is particularly helpful when you're trying to follow an algorithm, or when devising a counter example.
    • Which algorithms / techniques / heuristics taught in class are applicable to the problem at hand? When do they fail and for what reason?
    • Reduce the problem to a problem taught in class. Can the problem be represented as tree? a graph? a flow network? maybe to a less general instance of the problem itself (a graph with negative weight to a graph with unique, non-negative weights)?
    • The notion of sub-problem (divide-and-conquer, dynamic programming, induction) is a recurring theme in this class. Try to identify and solve the sub-problems of the problem at hand.
    • If you are still stuck, come to office hours. Sometimes just a brief meeting can get you pointed in the right direction (or help to back you up from a wrong path, to use a DFS analogy).
  4. When you write down your solution, re-read what you've written. Is the solution understandable? Does it answer specifically what you've been asked about? Your answers should be clear, and often they will be short.


  • We will use Piazza for online discussions and course announcements.
  • Make sure you don't post questions to piazza that give away solutions (or even give hints).
  • Piazza is best used for announcements, clarifications, and short queries. If you want to discuss problem solving, or need advice on how to get unstuck, please come to office hours! We are here to help you.


  • Several of the topics we teach, particularly the more advanced ones, are not covered in the standard Algorithms textbooks. Hence we will provide lecture notes covering all the material in this course.
  • However, we would like you to have a book to give you more detailed coverage. (Or to give you an alternative perspective if you find our own confusing!) We recommend you get one of the following:
    • Introduction to Algorithms, by Cormen, Leiserson, Rivest, and Stein (hereafter referred to as "CLRS"). It's big, it's fairly expensive, but it is the gold standard of algorithms books with a lot of material. Based on the Algorithms course at MIT.
    • Algorithms, by Dasgupta, Papadimitriou, and Vazirani (herafter referred to as "DPV"). Smaller, cheaper, more informal. A relatively new book based on Algorithms courses at UC Berkeley and UCSD. A preliminary (incomplete) version is available here.
  • Specific readings in CLRS and DPV will be listed on the course schedule. It is recommended that you skim the reading before lecture, with a more thorough read afterwards.
  • Other helpful material can be found in: Algorithm Design by J. Kleinberg and E. Tardos, Data Structures and Network Algorithms by R. E. Tarjan, Randomized Algorithms by Motwani and Raghavan, Programming Pearls by J. Bentley, Introduction to Algorithms: a Creative Approach by U. Manber, and the classic Aho-Hopcroft-Ullman book. See also some excellent lecture notes by Jeff Erickson at UIUC.

Your Health & Well-being

  • We want you to learn cool new things in the course, things that will be useful for your life and career. And we want you to have fun learning this material! Part of making sure you have the right experience involves taking care of yourself. Do your best to maintain a healthy lifestyle this semester by eating well, exercising, avoiding drugs and alcohol, getting enough sleep and taking some time to relax. This will help you achieve your goals and cope with stress.

    If you or anyone you know experiences any academic stress, difficult life events, or feelings like anxiety or depression, we strongly encourage you to seek support. Counseling and Psychological Services (CaPS) is here to help: call 412-268-2922 and visit Consider reaching out to a friend, faculty or family member you trust for help getting connected to the support that can help.

Accommodations for Students with Disabilities:

  • If you have a disability and are registered with the Office of Disability Resources, we encourage you to use their online system to notify us of your accommodations and also come and see us to discuss your needs as early in the semester as possible. We will work with you to ensure that accommodations are provided as appropriate. If you suspect that you may have a disability and would benefit from accommodations but are not yet registered with the Office of Disability Resources, we encourage you to contact them at

Other Policies

Lateness and Absence

  • Make-ups for the exams and the final must be arranged at least one week in advance, barring extreme situations. Make sure to document any health problems you might have. If you need special accommodations, please contact Prof. Sleator or Prof. Woodruff as early as possible.

Academic Integrity

  • We will assume that you understand the issues and do not need a detailed explanation here: in a nutshell, collaboration is healthy, but plagiarism and cheating are serious academic offenses with serious consequences. (And yes, doing web searches for homework solutions is cheating, as is looking at others' solutions for HWs where we do not allow collaboration.) If you cheat in the class we will penalize you and report you to the authorities. Issues will be handled in accordance with the University Policy on Academic Integrity. Please also see the the Carnegie Mellon Code on Academic Integrity.

Finally, feel free to contact any member of the course staff to clarify these policies.