Reverse Polish, or Postfix notation is commonly used in Computer Science, particularly in reference to Stacks - but what are stacks and how does postfix work? Professor David Brailsford takes us through it. Upside Down (Huffman) Trees: https://www.youtube.com/watch?v=umTbivyJoiI Quick Sort: https://www.youtube.com/watch?v=XE4VP_8Y0BU Getting Sorted: https://www.youtube.com/watch?v=kgBjXUE_Nwc http://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: http://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. See the full list of Brady's video projects at: http://bit.ly/bradychannels