In this assignment, I have implemented a distributed graph coloring algorithm using Java. The objective was to color a graph such that no two adjacent nodes share the same color using exactly 1 + Δ colors, where Δ is the maximum degree of any node in the graph. Each node autonomously determines its color by communicating with its neighbors.

The input file consists of the following structured data:

• First Line: Number of nodes (numNodes).
• Second Line: Maximum degree in the graph (maximalDegree).
• Subsequent Lines: Each line represents a node and lists its neighbors, along with the writing and reading ports for communication, formatted as:

  nodeID [[neighborId, writingPort, readingPort], …]
  

5
3
0 [[1, 6060, 13821], [2, 6067, 11111]]
1 [[0, 13821, 6060], [2, 6069, 13131]]
2 [[0, 11111, 6067], [1, 13131, 6069], [3, 12312, 70809]]
3 [[2, 70809, 12312], [4, 67679, 10101]]
4 [[3, 10101, 67679]]

The output file should list the nodes in ascending order with their respective colors, formatted as:

nodeId,nodeColor
nodeId,nodeColor
...

0,0
1,1
2,2
3,0
4,3

• A generic class representing a key-value pair.
• Implements Serializable for network transmission.

• Represents a graph node.
• Extends Thread or implements Runnable for distributed execution.
• Manages node ID, neighbors, and communicates with adjacent nodes to determine color.

• Handles the initial reading and parsing of the input file.
• Initiates the graph setup and starts the coloring process.
• Manages the orderly termination of the process and outputs the results.

• The entry point for running the coloring algorithm.
• Manages the lifecycle of the Manager class operations.

• Direct communication must be established between neighboring nodes using the specified ports.
• Only neighboring nodes can exchange messages, ensuring the algorithm runs in a truly distributed manner.