Graph
Welcome to the Graph project! This project focuses on implementing efficient algorithms for graph manipulation and analysis. It boasts two main algorithms: the Prim-Jarnik algorithm and the Page Rank algorithm, both designed to handle various types of graphs and produce accurate results.
Design Choices:
For the prim-jarnik algorithm, I used several new instances of the myDecorator class. I stored all cost integers in costDec, boolean variables dictating whether a node was visited in visitedDec, previous nodes in prevDec and entries in entryDec. These decorations made it much easier to store a lot of information without using messy data structures.
For the page rank algorithm, I handled sinks by adding edges from the sink to all other nodes and itself. I didn't use decorations for page rank as I used arrays instead (for current and prev rank).
Testing:
The JUnit tests in GraphTest check that all the methods work and also check for any exceptions that must be raised. All methods that work for the demo also work when I run my app.
The JUnit tests in MsfTest check if the Prim Jarnik algorithm works on an empty graph, graph with 1, 2, and more vertices. All graphs tested were undirected. The prim jarnik algorithm works the same for me as the demo.
The JUnit tests in MsfTest check if the Page Rank algorithm works on an empty graph, graph with 1, 2 vertices, graphs with sinks, graphs with edge-less vertices and more. All graphs tested were directed. The page rank algorithm works the same for me as the demo, including when loading "olympic_links".
To ensure a page has the lowest ranking of any vertex, steps can be taken to remove all of its incoming edges (or simply treat its number of incoming edges as 0). Hence, make the number of incoming edges to be 0 for the blacklisted page.
This way its page rank would be equal to only (1-d)/N and not be equal to that plus the sum of the amounts of page rank from other pages. It still could possibly get some additional pageRank if there is a sink (that connects to it with an edge). However, it will still have the lowest ranking as the sink will connect to all the other pages too (and also to the sink itself).