package CSP;

/**
 * Title:        NQueens
 * Description:  Class for NQueens CSP.
 * Copyright:    Copyright (c) 2005
 * Company:      MIT
 * @author Andreas Hofmann
 * @version 1.0
 */



import java.util.*;

public class NQueens extends CSP_rep
{
    
    int size = 0;

    public NQueens(int sz)
    {
	size = sz;
    }

    public void initialize()
    {
	// Initialize NQueens problem according to size.

	// Initialize variables and domains.
	variables = new ArrayList();
	domain = new NQueensDomain(size);
	constraints = new ArrayList();

	for (int col=0; col<size; col++) {
	    NQueensDomain var_domain = new NQueensDomain(size);
	    NQueensVariable new_var = new NQueensVariable(col, var_domain);
	    variables.add(new_var);
	}

	// Initialize constraints.
	ListIterator var1_iterator = variables.listIterator();

	while (var1_iterator.hasNext()) {
	    NQueensVariable var1 = (NQueensVariable)var1_iterator.next();

	    ListIterator var2_iterator = variables.listIterator();
	    
	    while (var2_iterator.hasNext()) {
		NQueensVariable var2 = (NQueensVariable)var2_iterator.next();

		if (var1 != var2)
		    constraints.add(new NQueensConstraint(var1, var2));
	    }
	}
    }

    public void print()
    {
	ListIterator var_iterator = variables.listIterator();

	while (var_iterator.hasNext()) {
	    NQueensVariable current_var = (NQueensVariable)var_iterator.next();
	    
	    System.out.println("col " + current_var.col);

	    List values = current_var.domain.domain_values;
	    ListIterator val_iterator = values.listIterator();
	    
	    System.out.println("rows: ");
	    while (val_iterator.hasNext()) {
		Integer current_val = (Integer)val_iterator.next();

		System.out.print(" " + current_val);
	    }
	    System.out.println();
	}
    }
}