This visualization is one of five that was used as a mini-tutorial in a Data Structures III class.  Last year was the first time it was used and students were encouraged to use it as basis for creating visualizations of their own.  Time was limited, so this year I allocating more time to help the students devise their own animations.

On the introductory page, the definition of the algorithm is presented and then its characteristics are listed. In the animation, two different views of the algorithm are presented  to illustrate the execution of Dijkstra’s algorithm.

The animation includes a demo of how the algorithm works with related code and then students can create their graphs, weights and edges and run the algorithm with related code appearing. The instructions given are below

“Then select either step or run to execute the algorithm. Note that it starts by assigning a weight of infinity to all nodes, and then selecting a source and assigning a weight of zero to it. As nodes are added to the set for which

shortest paths are known, their colour is changed to red. When a node is selected, the weights of its neighbours are relaxed .. nodes turn green and flash as they are being relaxed. Once all nodes are relaxed, their predecessors

are updated, arcs are turned green when this happens. The cycle of selection, weight relaxation and predecessor update repeats itself until all the shortest path to all nodes has been found.”

There are four other visualization on this site that can be used similarly.

I found that the students were interested but that I needed to spend more class time explaining visualization development.