public class Node
{
	private Puzzle puzzles;
	private Node puzzle_parent;
	private Node[] puzzle_children;
	private int puzzle_numChildren;
	private int puzzle_number;
	private int puzzle_pathCost;
	private int puzzle_nodeCost;
	
	public	Node(Puzzle p) {
		puzzles = p;
		puzzle_number = 0;
		puzzle_nodeCost = 0;
		puzzle_numChildren = 0;
		puzzle_pathCost = 0;
		puzzle_children = new Node[4];//Max 4 way to move

	}
	public void	expand() {

		for (int i = 1; i <= 8; ++i) {
			if (puzzles.legal(i)) {
				Puzzle puzzle = new Puzzle(puzzles.number);
				puzzle.move(i);
				Node child = new Node(puzzle);

				child.puzzle_parent = this;
				child.puzzle_number = i;
				child.puzzle_pathCost = puzzle_pathCost + 1;

				// Using A* search,may change to another search
				child.puzzle_nodeCost = puzzle_pathCost + puzzle.totalCost();
				
				puzzle_children[puzzle_numChildren++] = child;
			}
		}
	}
	public Puzzle getPuzzle() {
		return puzzles;
	}
	public Node getParent() {
		return puzzle_parent;
	}
	public int getNumChildren() {
		return puzzle_numChildren;
	}
	public Node	getChild(int i) {
		return puzzle_children[i];
	}
	public int getPuzzleNumber() {
		return puzzle_number;
	}
	public int	getCost() {
		return puzzle_nodeCost;
	}

}