package com.neel.task1;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class FlatIntegerArray {

	/**
	 * @param inputArray
	 * @return
	 * @throws IllegalArgumentException
	 */
	public static Integer[] flatten(Object[] inputArray) throws IllegalArgumentException {

		if (inputArray == null)
			return null;

		List<Integer> flatList = new ArrayList<Integer>();

		for (Object element : inputArray) {
			if (element instanceof Integer) {
				flatList.add((Integer) element);
			} else if (element instanceof Object[]) {
				flatList.addAll(Arrays.asList(flatten((Object[]) element)));
			} else {
				throw new IllegalArgumentException("Input must be an array of Integers or nested arrays of Integers");
			}
		}
		return flatList.toArray(new Integer[flatList.size()]);
	}

	/**
	 * @param inputArray
	 * @return
	 * @throws IllegalArgumentException
	 */
	public static ArrayList<Integer> flattenList(Object[] inputArray) throws IllegalArgumentException {

		if (inputArray == null)
			return null;

		List<Integer> flatList = new ArrayList<Integer>();

		for (Object element : inputArray) {
			if (element instanceof Integer) {
				flatList.add((Integer) element);
			} else if (element instanceof Object[]) {
				flatList.addAll(Arrays.asList(flatten((Object[]) element)));
			} else {
				throw new IllegalArgumentException("Input must be an array of Integers or nested arrays of Integers");
			}
		}
		return (ArrayList<Integer>) flatList;
	}
}