/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package recyclednumbers;

import java.util.HashSet;

/**
 *
 * @author vandit
 */
public class RecycleNumbers {

    private HashSet<String> numbers = new HashSet<String>();
    private HashSet<String> initialTempNumbers = new HashSet<String>();
    private HashSet<String> finalTempNumbers = new HashSet<String>();

    HashSet<Pair> numberPairs = new HashSet<Pair>();


    private void findRecycledNumbers(int start, int end, int places) {


        for (int i = start; i <= end; i++) {
            String initialNumber = Integer.toString(i);
            //if (!(numbers.contains(initialNumber) || finalTempNumbers.contains(initialNumber))) {

                StringBuffer tempNumber = new StringBuffer(initialNumber);
                int len = tempNumber.length();
                int startIndexToMove = len - places;
                String tempString = tempNumber.substring(startIndexToMove);
                if ((places == 1 && tempString.equals("0")) || tempString.charAt(0) == '0') {
                    continue;
                }
                tempNumber.delete(startIndexToMove, len);
                String finalTempNumber = tempString + tempNumber.toString();

                if (! (finalTempNumber.equals(initialNumber) || Integer.parseInt(finalTempNumber) > end || Integer.parseInt(finalTempNumber) < Integer.parseInt(initialNumber))) {
                    numbers.add(initialNumber);
                    finalTempNumbers.add(finalTempNumber);
                    Pair pair = new Pair(finalTempNumber,initialNumber);
                    numberPairs.add(pair);
                }
            }

        

    }

    public HashSet<Pair> findAllRecycledNumbers(int start, int end) {
        int length = Integer.toString(start).length();
        for (int i = 1; i < length; i++) {
            findRecycledNumbers(start, end, i);
        }
        return numberPairs;
    }
}

package com.codejam2012;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class FileUtils {
	
	
	public static String readFile(String fileName){
		FileReader reader = null;
		String temp = null;
		try {
			reader = new FileReader(fileName);
		} catch (FileNotFoundException e1) {
			e1.printStackTrace();
		}
	    StringBuffer strContent = new StringBuffer("");
	    
	    try 
	    {
	      
	      BufferedReader bufferedReader = new BufferedReader(reader);
	      temp =bufferedReader.readLine();
	      while (temp != null)
	      {		    	  
	    	  strContent.append(temp + "\n");
	    	  temp =bufferedReader.readLine();
	      }
	      
	    } 
	    catch (Exception e) 
	    {
	      System.out.println(e);
	    }
	    
	    return strContent.toString();
	}

	public static void appendToFile(String outputFileName, String dataToPrint) {
						 
		File file =new File(outputFileName);
		if(!file.exists()){
			try {
				file.createNewFile();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		
		FileWriter fileWritter;
		try {
			fileWritter = new FileWriter(outputFileName,true);
			BufferedWriter bufferWritter = new BufferedWriter(fileWritter);
	        bufferWritter.write(dataToPrint);
	        bufferWritter.close();
	        fileWritter.close();
	        
		} catch (IOException e) {
			e.printStackTrace();
		}
	        
		
		
	}

	public static void deleteFile(String outputFileName) {
		File file =new File(outputFileName);
		if(file.exists()){
			file.delete();
		}
		
	}
	

}
