MapReduce - Grouping Nodes based on number of neighbors

This project implements a simple graph algorithm that needs two Map-Reduce jobs. A directed graph is represented as a text file where each line represents a graph edge.

For example,

First, for each graph node, we compute the number of node neighbors.

Then, we group the nodes by their number of neighbors and for each group we count how many nodes belong to this group.

The result will have lines such as: