Some mistakes in colab 1

[AngusMonroe]

1. For Q4, networkx closeness centrality returns the normalized closeness directly, which is different from the raw (unnormalized) one that we learned in the lecture. You should add closeness = closeness * (G.number_of_nodes() - 1) in your code.
2. For Q6, you directly used edge_1 in is_neg_edge(), which causes your outputs to be wrong.

[hdvvip]

Thanks Angus for the comment,

1. Following the equation in Q4, the calculation should be
   raw closeness centrality(node) = 1 / sum(distance from node to all other nodes)
   https://neo4j.com/docs/graph-data-science/current/algorithms/closeness-centrality/

Last version, I think the implement version by networkX is better so I just use the normalized version by NetworkX
In the new commit, I added the raw closeness centrality calculation following the equation in Q4.

2. You're right. Thank you so much!

[SLKyrim]

For Q3, I think r0 should be updated with the r values of the neighbors of node 0, not r0 itself.

[hdvvip]

Thank you!
I just fix that in the new commit.