Graph algorithms: semi-scaffolded versions

[ttaiv]

Idea for new versions of graph algorithms exercises (Prim, Dijkstra, BFS, DFS). These version are between scaffolded versions (which currently exist only for Prim and Dijkstra) and regular versions in terms of how much the student is helped.

A "semi-scaffolded" exercise version would have the following properties:

• There is no visualization of the data structure used to implement fringe (PQ, FIFO queue or call stack), like in regular versions.
• User adds graph nodes and edges to fringe by clicking them once, like in scaffolded versions.
• User adds graph nodes to the spanning tree by clicking them again, similar to what pressing "dequeue" in scaffolded versions does.

This means that these exercise versions would implement fringe just like scaffolded versions but state of the data structure would need to be maintained by user.

[ttaiv]

Relaxation in these exercises could be performed with the following logic. If user clicks edge (u,v)

• and u is part of spanning tree and v fringe: make u the new parent of v
• something else: show error alert to user