Due Wednesday, December 8th at 11:59pm.
In this lab, you will develop your understanding of graphs and graph algorithms. You will do this by implementing the three algorthims we discussed in class and apply them to exploring the map of Swarthmore College’s north campus. You will then provide written examples of how some of these graph algorithms work.
As usual, you can find a link to your GitHub repository on Teammaker.
The URL for your repository will be
git@github.swarthmore.edu:cs35-f21/lab09-<your-teamname>
Your starting repository contains the following files. The bold files are the ones you will need to implement:
adjacencyListGraph.h
and adjacencyListGraph-inl.h
: An implementation of a directed, labeled, weighted graph in the form of a template class.
adjacencyListUndirectedGraph.h
and adjacencyListUndirectedGraph-inl.h
: An implementation of an undirected, labeled, weighted graph in the form of a template class.
adts/
: As usual, this directory contains the definitions of ADT interfaces as well as supplied implementations of the ADTs we’ve previously discussed.
graphAlgorithms.h
/graphAlgorithms-inl.h
: The definitions of the graph search algorithms you will implement.
main.cpp
: Where you will write the main program for this lab.
Make sure you have examined adts/graph.h
to understand the interface you will be using in this lab.
For this final lab assignment of the semester, we are allowing you to
design your main
program as you see fit. However, you must have
helper functions so that your main
program is concise and easy to
understand. You should declare your helper functions by using function
prototypes above the definition of the main
program. You should
incrementally add to your main
program as you make progress on
implementing the graph algorithms.
In main.cpp
create a graph to represent the college map as shown
above. Do this by creating a new instance of the
AdjacencyListUndirectedGraph
class and then calling the graph’s
insertVertex
and insertEdge
methods. For an undirected graph, you
only need to insert the edge between any two vertices one time. There
are 8 vertices and 10 edges in this graph.
Next, your main
program should provide the user with a menu to allow
them to interact with the graph associated with the College map:
$ ./main
Let's explore Swarthmore's north campus
1. Reachability from one building to another
2. Shortest length path from one building to another
3. Distances from one building to all others
0. Quit
Choice:
The menu should ensure that the user types in a valid integer 0-3. You may assume that the user always provides an integer. The menu should be repeatedly presented until the user chooses to quit.
Once your menu is working and your graph is created, start working on the graph algorithms.
In graphAlgorithms-inl.h
implement reachableDFS
.
Then in your main
program add the functionality to allow the user to
call this function:
Let's explore Swarthmore's north campus
1. Reachability from one building to another
2. Shortest length path from one building to another
3. Distances from one building to all others
0. Quit
Choice: 1
Enter the first building: Martin
Martin is not a vaild building code
The building codes are: Par Trot Kohl Sing Ber LPAC Mar Sci
Let's explore Swarthmore's north campus
1. Reachability from one building to another
2. Shortest length path from one building to another
3. Distances from one building to all others
0. Quit
Choice: 1
Enter the first building: Mar
Enter the second building: Sing
Sing is reachable from Mar
You must ensure that the user provides a valid building code. If they make a mistake, you should list out all of the valid building codes, as shown above.
In graphAlgorithms-inl.h
implement shortestLengthPathBFS
.
Then in your main
program add the functionality to allow the user to
call this function:
Let's explore Swarthmore's north campus
1. Reachability from one building to another
2. Shortest length path from one building to another
3. Distances from one building to all others
0. Quit
Choice: 2
Enter the first building: Sci
Enter the second building: Trot
The shortest length path is: Sci Sing Trot
Again, you must ensure that the user provides a valid building code.
Remember that BFS will find the path with the fewest links, not the cheapest one.
In graphAlgorithms-inl.h
implement singleSourceShortestPath
.
Then in your main
program add the functionality to allow the user to
call this function:
Let's explore Swarthmore's north campus
1. Reachability from one building to another
2. Shortest length path from one building to another
3. Distances from one building to all others
0. Quit
Choice: 3
Enter the building to start from: Kohl
Distance from Kohl to all other buildings
Sci:6
Mar:5
LPAC:2
Trot:3
Par:4
Ber:2
Sing:4
Kohl:0
Again, you must ensure that the user provides a valid building code.
Once your main
program is functioning correctly, you are ready to
move on to the written portion of the assignment.
Give your answers to the following questions in a file named
WrittenLab.pdf
. You may use the provided WrittenLab.tex
file;
running make WrittenLab.pdf
will produce your document. You may
also use some other program to generate the document.
Perform a breadth-first search of the graph starting from vertex A. Give the number of steps to reach every other vertex. Additionally, give the order in which the vertices are first witnessed; that is, give the order in which they first enter the queue (and not necessarily the order in which they are explored).
Use Dijkstra’s algorithm (for finding single source shortest paths) on this graph starting from vertex A. Give the cost of the least-cost path to every other vertex. Additionally, give the order in which the vertices are first witnessed; that is, give the order in which they first enter the queue (and not necessarily the order in which they are explored).
Give two valid topological sorts of this graph.
When you are finished, you should have
An implementation of the three graph algorithms
A main.cpp
program that meets the specifications detailed above
No memory errors or leaks
A write-up answering the above graph algorithm questions