Graph Teacher

This was a class project. It was an educational graph algorithm teacher application. Only graph editing, Breadth-first, and Depth-first was implemented. I wrote this using delphi 7.

It is an good tool in the classroom to teach Depth-first/Breadth-first searches.

An english translation can be downloaded from here [en] .

The original hungarian version can be downloaded from here [hu] .

Features

• Editor: (editor.exe)
• Can create weighted/unweighted graphs
• Can create directed/undericted graphs
• While editing the graph it is possible to drag and drop the nodes around
• There is also a matrix representation that can be edited
• Algorithm teacher: (algorithms.exe/algoritmusok.exe)
• Can open up graphs created by the editor
• Each algorithm is composed of multiple smaller windows that can be moved and resized inside the main window
• All presented algorithms contain:
• The Adjacency Matrix of th Graph (A gráf szomszédsági mátrixa [hu])
• a graphical representation of the graph with movable nodes. The color of each node and edge gives information about the state of the simulation.
• a description window for the algorithm (Magyarázat [hu])
• a pascal-like pseudocode window (Az algoritmus [hu])
• it is possible to step trough the algorithm using the Control window. It is like in most debuggers, but all information is presented in a much clearer way. (Indítás = Start, Tovább = Next step, Végeredmény = Results)
• a result output window (Kimenet [hu])
• Depth-first search:
• There is a "visited" array window (T=visited, F=not visited) (A "Láttam" tömb [hu])
• The call stack of the backtracking is shown in the Call Stack and local variables window. (Verem [hu])
• The current considered node is colored green (the node that is on the top of the backtracking stack)
• Nodes that have been visited in the past are colored yellow
• The current edge that is considered is colored red
• The edges that led to the current node from the starting node are colored blue
• Breadth-first search:
• There is a 'visited' array window just as for the Depth-first search
• There is a FIFO window. The first item that will come out of the FIFO buffer is marked with a 'S' (K in [hu]), and the last item to go in is marked with a 'V' (E in [hu]) (A várakozási sor [hu])
• Nodes that have been visited in the past are colored green
• The current considered node is colored yellow (the one in the Node [en] / Szögpont [hu] variable)
• all the nodes in the FIFO buffer are colored purple
• Graphs are saved into their own text files. The list of accessible graphs is kept in graphs.txt[en]/grafok.txt[hu]