extension.txt

The problem we solved:

The average distance to Kevin Bacon under unweighted condition.

How we solve it:

We first read all the actors and their corresponding movies from the file 
movie_casts.tsv. After we load the file to our ActorGraph, we have two 
unordered_map to store information. One contains all the actors and the 
other one contains all the movies. In here, we'll use the unordered_map 
that stores all the actors, which an actor list. We use an iterator to go 
through all the actors in the actor list. We use a for loop here. For 
each actor nodes in the iterator, we uses BFS to find the shortest path, 
like we do in pathfinder to find in unweighted case. We start from actor 
BACON, KEVIN (I) and end to the actor the iterator is on so that we can 
find the distance between BOCAN, KEVIN (I) to one specific actor. Then 
add the distance to a variable called totalDist. After we iterate through 
all the actors, we get the total distance of the shortest paths starting 
from BACON, KEVIN (I) to all the other actors and then we divided the 
total distance by size-1 to get average distance. In here, the size is 
the size of unordered_map containing all the actors.

How we test it:

we make the executable extension file first and run it with the tsv file 
movie_casts.tsv so that it can load the casts. Inside our program, we
print out the final result, which is the average distance to BACON, KEVIN(I).
The commands we use to test are listed below.

Commands:

make extension
./extension movie_casts.tsv

In genearl it takes around 50s to complete the entire search