import java.util.Random;

public class Q1 {

	public static void main(String[] args) {
		//calling to method - build and initiaize a Node-List
		int[] values = new int[]{4,3,2,6};
		Node<Integer> l1 = valuesToList(values);
		Node<Integer> l2 = valuesToList(new int[]{10,11,19,1,7,100});	//short way to initialize
		Node<Integer> l3 = null;

		System.out.println("----BEFORE----");
		System.out.print("l1: ");
		print(l1);
		System.out.print("l2: ");
		print(l2);

		Node<Integer> tmp1 = l1;
		Node<Integer> tmp2 = l2;

		int k = 0;
		while(tmp1!=null) {
			k = tmp1.getValue();
			//if k is even
			if(k%2==0) {
				deleteByPosition(tmp2, k);
			}
			//if k is odd
			else {
				Node<Integer> tmp = byPosition(tmp2, k);

				if(tmp!=null) {
					if(l3==null)	//1st node in l3-chain
						l3 = new Node<Integer>(tmp.getValue());
					else
						l3.setNext(new Node<Integer>(tmp.getValue()));
				}

			}
			tmp1 = tmp1.getNext();
		}
		System.out.println("-----AFTER----");
		System.out.print("l1: ");
		print(l1);
		System.out.print("l2: ");
		print(l2);
		System.out.print("l3: ");
		print(l3);

	}	//end of main

	/*
	 * deletes a node in the given position
	 * return the altered node-list
	 */
	public static Node<Integer> deleteByPosition(Node<Integer> head, int pos){
		Node<Integer> tmp = head;
		Node<Integer> previous = byPosition(head, pos-1);
		Node<Integer> oneAfter = byPosition(head, pos+1);
		if(oneAfter!=null)
			previous.setNext(oneAfter);
		return tmp;

		//return previous.setNext(previous.getNext().getNext());
	}

	/*
	 * return the node in the given position in a node-list
	 * returns the altered node-list
	 */
	public static Node<Integer> byPosition(Node<Integer> head, int pos){
		while(pos>1 && head!=null) {
			pos--;
			head = head.getNext();
		}
		return head;
	}

	/*
	 * prints a given node-list
	 */
	public static void print(Node<Integer> chain) {
		while(chain!=null) {
			System.out.print(chain.getValue()+"->");
			chain=chain.getNext();
		}
		System.out.print("null"+"\n");
	}
	/*
	 * builds a new chain of nodes of random genarted numbers
	 * input length
	 */
	public static Node<Integer> randomList(int length){
		Random rnd = new Random();
		int val = rnd.nextInt();
		Node<Integer> head = new Node<Integer>(val);
		Node<Integer> tmp = head;
		while(length>0) {
			length--;
			val = rnd.nextInt();
			tmp.setNext(new Node<Integer>(val));
			tmp = tmp.getNext();
		}
		return head;
	}
	//--------Util methods to initialize the question--------------------------//

	/*
	 * builds a new chain of nodes
	 * input - array of values
	 */
	public static Node<Integer> valuesToList(int[] values){
		Node<Integer> head = new Node<Integer>(values[0]);
		Node<Integer> tmp = head;

		for (int i = 1; i < values.length; i++) {
			tmp.setNext(new Node<Integer>(values[i]));
			tmp = tmp.getNext();
		}
		return head;
	}

}