/*
 * 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 fixjava;

import java.util.Iterator;

/**
 * Create an iterator that keeps track of the current index into the Iterable.
 * 
 * Usage:
 * 
 * <code>

	public static void main(String[] args) {
	
		// Iterate over a list:
		ArrayList<String> list = new ArrayList<String>();
		list.add("apple");
		list.add("banana");
		list.add("pear");
		for (IndexedItem<String> it : IndexedItem.iterate(list))
			System.out.println(it.getIndex() + ": " + it.getItem());
			
		// Iterate over an array:
		String[] arr = new String[] {"a", "b", "c"};
		for (IndexedItem<String> it : IndexedItem.iterate(arr))
			System.out.println(it.getIndex() + ": " + it.getItem());
	}

   </code>
 * 
 * @author (c) Luke Hutchison 2010. Covered under the BSD license.
 * 
 * @param <T>
 *            The type of the Iterable.
 */
public class IndexedItem<T> {
	private T item;
	private int index = -1;

	/** Get the current item in the iteration. */
	public T getItem() {
		return item;
	}

	/** Get the index of the current item (zero-indexed). */
	public int getIndex() {
		return index;
	}

	private static class IndexedIterator<U> implements Iterable<IndexedItem<U>>, Iterator<IndexedItem<U>> {

		private final Iterator<U> collectionIter;
		private final IndexedItem<U> currItem = new IndexedItem<U>();

		public IndexedIterator(Iterable<U> collection) {
			this.collectionIter = collection.iterator();
		}

		public IndexedIterator(final U[] array) {
			collectionIter = new Iterator<U>() {
				U[] arr = array;
				IndexedItem<U> it = currItem;

				@Override
				public boolean hasNext() {
					return it.index + 1 < arr.length;
				}

				@Override
				public U next() {
					return arr[it.index + 1];
				}

				@Override
				public void remove() {
					for (int i = it.index + 2; i < arr.length; i++)
						arr[i] = arr[i + 1];
				}
			};
		}

		@Override
		public Iterator<IndexedItem<U>> iterator() {
			return this;
		}

		@Override
		public boolean hasNext() {
			return collectionIter.hasNext();
		}

		@Override
		public IndexedItem<U> next() {
			currItem.item = collectionIter.next();
			currItem.index++;
			return currItem;
		}

		@Override
		public void remove() throws UnsupportedOperationException, IllegalStateException {
			collectionIter.remove();
			currItem.index--;
			currItem.item = null;
		}
	}

	/** Iterate over an Iterable<T> and keep track of the index */ 
	public static <T> Iterable<IndexedItem<T>> iterate(Iterable<T> collection) {
		return new IndexedIterator<T>(collection);
	}

	/** Iterate over an array T[] and keep track of the index */
	public static <T> Iterable<IndexedItem<T>> iterate(T[] array) {
		return new IndexedIterator<T>(array);
	}
}

