/*
 * 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 qualification.q3;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

/**
 * Created by IntelliJ IDEA.
 * User: ofer
 * Date: 14/04/12
 * Time: 20:31
 * To change this template use File | Settings | File Templates.
 */

public class Q3Solver {
    
    private Set<String> mapping;

    public Q3Solver(){
        mapping = new HashSet<String>();
    }
    
    public int solve(int a,int b){
        int res = 0;
        for (int i = a ; i <= b ; i++){
            res+= getNumberOfLegalRecycled(  b,  i);
        }
        return res;
    }

    private int getNumberOfLegalRecycled( int b, int num) {
        String numString = ""+num;
        int numDigits = numString.length();
        int res = 0;
        for (int i = 0 ; i < numDigits - 1 ; i++){
            String perm = numString.substring(numDigits - i - 1) + numString.substring(0,numDigits - i -1 );
            Integer newNum = Integer.parseInt(perm);
            String test = newNum+"";
            if (test.length() == numDigits){          //checks that there are no leading zeros
                if ( num != newNum  && newNum > num && newNum <= b){
                    if (!mapping.contains(newNum+","+num) && !mapping.contains(num+","+newNum))    {
                        res++;
                        mapping.add(num+ "," +newNum);
                        mapping.add(newNum +"," +num);
                    }

                }

            }
        }
    return res;
    }

}
