Submitted by ajalon on 17 March 2010 – 12:18pm

The AlgoViz.org Hall of Fame honors exemplary AVs. The list is drawn from the winners of the annual AlgoViz Awards, selected by users and developers of Algorithm Visualizations.

2010 Inductees

You can see a video showcasing the 2010 AlgoViz Award Winners.

Honorary Inductee:

Sorting Out Sorting, Ronald Baecker, University of Toronto, 1980

This classic video is generally credited as the original “algorithm animation”. A video with narration, it showing “moving bars” to demonstrate the workings of several sorting algorithms and their relative performance.

AlgoViz Awards for 2010:

Binary Heap Tutorial, TRAKLA2, Aalto University

A complete tutorial for array-based Binary Heaps. Uses TRAKLA2 visualizations for interactive exercises on Insert, DeleteMax, BuildHeap, and HeapSort algorithms.

Interactive Hashing Tutorial, Algorithm Visualization Research Group, Virginia Tech

A complete tutorial for teaching hashing, largely based on the presentation in “A Practical Introduction to Data Structures and Algorithm Analysis” by Clifford A. Shaffer. A series of HTML pages takes the reader through the topics of hash functions, open vs closed hashing, collision resolution, deletion. The web pages are interspersed with visualizations that demonstrate a variety of hash functions and collision resolution methods, as well as applets that show aspects of the performance for the various methods.

Closest Pair of Points, ALVIE, University of Florence

Demonstrates a divide and conquer algorithm for computing the closest pair of points within a speciﬁed set of points in the Euclidean plane. C-like pseudo-code is included. The visualization tries to mimic as far as possible animation of the algorithm used by Prof. Ottmann at the University of Freiburg. The visualization uses color to distinguish nodes within a vertical/horizontal strip from nodes out of the strip. Colors are also used to emphasize which nodes and distances are currently under examination. The user can go backward and forward, can zoom in and zoom out, and can set bookmarks. This visualization is easily conﬁgurable and localizable.

AVL-tree Insertion Exercise, TRAKLA2, Aalto University

A collection of exercises related to searching, inserting into, and deleting from AVL Trees. User points at the appropriate node, or drags-and-drops nodes as appropriate.

Radix Sort, Algorithm Visualization Research Group, Virginia Tech

A visualization of the Radix Sort algorithm, as presented in “A Practical Introduction to Data Structures and Algorithm Analysis” by Clifford A. Shaffer. Shows each phase of the radix sort process. This includes (for each digit) generating counts for each digit value and showing how the counts are used to move keys to the output array for that pass. A brief description of each step is synchronized to the step-by-step animation.

Quicksort, Algorithms in Action, University of Melbourne

The AV works well and shows intuitive visualizations. Four separate windows are launched. They are the Explanation window, the Algorithm window (showing program code), the “AIA: Quicksort window” (for showing an animation) and the Help window. In the Algorithm window the user can see the program code either in real program code mode or in natural language mode. Assistive comments are available that explain the sorting process. Clicking parts of the program code gives English explanation in the Explanation window. The Help window offers advice about what the user can do with each clickable item in Algorithm window or “AIA: Quicksort window”. The “AIA: Quicksort window” shows a set of randomized numbers and right above them vertical bars with varying length that corresponds to the size of each number. In the windows there are also buttons with names Step, Back, Run, Pause and Reset, as well as set of menu controls for ﬁne-tuning. The basic functionality is based on seeing ﬁrst the vertical bars in a randomized order. Then step by step the algorithm will arrange the bars into ascending or descending order.