RLFTester.java

import java.io.*;
import java.util.*;

		class ColEdge
			{
			int u;
			int v;
			}

public class RLFTester
		{

		public final static boolean DEBUG = false;

		public final static String COMMENT = "//";

		public static void main( String args[] )
			{
			if( args.length < 1 )
				{
				System.out.println("Error! No filename specified.");
				System.exit(0);
				}


			String inputfile = args[0];

			boolean seen[] = null;

			//! n is the number of vertices in the graph
			int n = -1;

			//! m is the number of edges in the graph
			int m = -1;

			//! e will contain the edges of the graph
			ColEdge e[] = null;

			try 	{
			    	FileReader fr = new FileReader(inputfile);
			        BufferedReader br = new BufferedReader(fr);

			        String record = new String();

					//! THe first few lines of the file are allowed to be comments, staring with a // symbol.
					//! These comments are only allowed at the top of the file.

					//! -----------------------------------------
			        while ((record = br.readLine()) != null)
						{
						if( record.startsWith("//") ) continue;
						break; // Saw a line that did not start with a comment -- time to start reading the data in!
						}

					if( record.startsWith("VERTICES = ") )
						{
						n = Integer.parseInt( record.substring(11) );
						if(DEBUG) System.out.println(COMMENT + " Number of vertices = "+n);
						}

					seen = new boolean[n+1];

					record = br.readLine();

					if( record.startsWith("EDGES = ") )
						{
						m = Integer.parseInt( record.substring(8) );
						if(DEBUG) System.out.println(COMMENT + " Expected number of edges = "+m);
						}

					e = new ColEdge[m];

					for( int d=0; d<m; d++)
						{
						if(DEBUG) System.out.println(COMMENT + " Reading edge "+(d+1));
						record = br.readLine();
						String data[] = record.split(" ");
						if( data.length != 2 )
								{
								System.out.println("Error! Malformed edge line: "+record);
								System.exit(0);
								}
						e[d] = new ColEdge();

						e[d].u = Integer.parseInt(data[0]);
						e[d].v = Integer.parseInt(data[1]);

						seen[ e[d].u ] = true;
						seen[ e[d].v ] = true;

						if(DEBUG) System.out.println(COMMENT + " Edge: "+ e[d].u +" "+e[d].v);

						}

					String surplus = br.readLine();
					if( surplus != null )
						{
						if( surplus.length() >= 2 ) if(DEBUG) System.out.println(COMMENT + " Warning: there appeared to be data in your file after the last edge: '"+surplus+"'");
						}

					}
			catch (IOException ex)
				{
		        // catch possible io errors from readLine()
			    System.out.println("Error! Problem reading file "+inputfile);
				System.exit(0);
				}

			for( int x=1; x<=n; x++ )
				{
				if( seen[x] == false )
					{
					if(DEBUG) System.out.println(COMMENT + " Warning: vertex "+x+" didn't appear in any edge : it will be considered a disconnected vertex on its own.");
					}
				}
				//! At this point e[0] will be the first edge, with e[0].u referring to one endpoint and e[0].v to the other
				//! e[1] will be the second edge...
				//! (and so on)
				//! e[m-1] will be the last edge
				//!
				//! there will be n vertices in the graph, numbered 1 to n

				//! INSERT YOUR CODE HERE!
				GreedyRLF rlf = new GreedyRLF(e);



			}

		}