public class Node
{
	private Node parent;
	public Node[] children;
	private int numChildren;
	private int number;
	private int pathCost;
	private int nodeCost;
	private String nodename;
	public int a;
	public int b;
	public int movetiems = 0;
	public int traveltimes = 0;
	public	Node() {
		
		number = 0;
		nodeCost = 0;
		numChildren = 0;
		pathCost = 0;
		children = new Node[3];//Max 3 way to move
		nodename = new String("");
	}/*
	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.parent = this;
				child.number = i;
				child.pathCost = pathCost + 1;

				// Using A* search,may change to another search
				//child.nodeCost = pathCost + puzzle.totalCost();
				
				//children[numChildren++] = child;
			}
		}
	}*/
	public void addChild(String name){
		Node child = new Node();
		child.parent = this;
		child.nodename = name;
		children[numChildren++] = child;		
	}
	public void addChild(String name,int value){
		addChild(name);
		children[numChildren-1].nodeCost = value;
	}
	public void setCost(int c){
		nodeCost = c;
	}
	public Node getParent() {
		return parent;
	}
	public int getNumChildren() {
		return numChildren;
	}
	public Node	getChild(int i) {
		return children[i];
	}
	public int getPuzzleNumber() {
		return number;
	}
	public int	getCost() {
		return nodeCost;
	}
	public void setName(String n){
		nodename = n;
	}
	public Node getNode(String name){
		for(int i=0;i<numChildren;i++){
			if(children[i].getName().equals(name))
				return children[i];			
		}
		return null;
	}
	public String getName(){
		return nodename;
	}
	public int getValue(int alpha,int beta){
		
		boolean max = false;
		String minmax = "Min";
		if((nodename.charAt(0)-65)%2==0){
			max = true;		
			minmax = "Max";
		}
		if(nodeCost!=0){
				alpha = nodeCost;
				beta = nodeCost;			
			if(max)
				if(alpha<this.parent.b)
				this.parent.b = alpha;
			else
				if(beta>this.parent.a)
					this.parent.a = beta;
			System.out.println("Unexpanding "+minmax+" Node "+ nodename+" alpha="+alpha+" Beta="+beta);
			return nodeCost;
		}else{
			a = alpha;
			b = beta;
		}		
		int value = 0;
			for(int i=0;i<numChildren;i++){
				traveltimes++;
				if(b<=a)
					if(max)
						System.out.println("Skipping expansion of Node "+children[i].getName()+" because it cannot make alpha higher");
					else
						System.out.println("Skipping expansion of Node "+children[i].getName()+" because it cannot make beta lower");
				else{
					System.out.println("Expanding "+minmax+" Node "+ nodename+" alpha="+a+" Beta="+b);				
					children[i].getValue(a,b);
				}	
			}			
			
		if(allChildHaveNumber()){
			if(max)
				value = getMaxFromChild();
			else
				value = getMinFromChild();
			
			nodeCost = value;
		}
		
		System.out.println("Expanding "+minmax+" Node "+ nodename+" alpha="+a+" Beta="+b);
		if(nodeCost >alpha)
			alpha = nodeCost;
		if(nodeCost <beta)
			beta = nodeCost;
		if(!nodename.equals("A1")){
		if(max){
			this.parent.b = alpha;
			this.parent.movetiems++;
		}
		else
			if(b>this.parent.a){
				this.parent.a = b;
				this.parent.movetiems++;
			}
		}
		return a;
		
	}
	public boolean allChildHaveNumber(){
		boolean right = true;
		for(int i=0;i<numChildren;i++){
			if(children[i].nodeCost == 0)
				right = false;				
		}		
		return right;
	}
	public boolean someChildHaveNumber(){
		boolean right = false;
		for(int i=0;i<numChildren;i++){
			if(children[i].nodeCost != 0)
				right = true;				
		}		
		return right;
	}	
	public int getMaxFromChild(){
		int max = 0;
		for(int i=0;i<numChildren;i++){
			if(children[i].nodeCost > max)
				max = children[i].nodeCost;								
		}		
		return max;
	}
	public int getMinFromChild(){
		int min = 32767;
		for(int i=0;i<numChildren;i++){
			if(children[i].nodeCost <min)
				min = children[i].nodeCost;								
		}		
		return min;
	}	
}