This collection of videos includes lectures from Fall 2010 and class sessions Fall 2012. Class sessions are based on the corresponding lectures, and cover submitted questions, clarifications, additional topics, interactive activities, and open problems. Students are asked to view the relevant lecture videos, recorded in Fall 2010, prior to attending each class. The lecture videos and class videos correspond numerically (e.g., Lecture 1 before Class 1, Lecture 2 before Class 2, and so on). The lecture and class session videos are also available an integrated format (synced notes, slides, and video) on Prof. Demaine's website for this course. License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu