/**
 * A subproblem is a formula and an (partial) assignment with the same number of variables.
 * Useful to model a subproblem of a larger SAT problem consisting of the formula without
 * an assignment. The (partial) assignment specifies a subtree of the total solution space
 * for the larger problem.
 *
 * @author Danielle and Dr. Lobo
 * @version 2008.01.10
 *
 * * Modification log:
 * 1. 2008/02/07 Added constructor SubProblem(SubProblem s) which copy a SubProblem
 * 0. Created 2008/Jan by Andrea Lobo (AL) and Danielle Socha (DS)
 */
public class SubProblem
{
    Formula f;
    Assignment partialAssignment;

    public SubProblem()
    {
    }

    /**
     * Constructor for SubProblem
     *
     * @param inputF input file name containg the
     *                      information for the formula;
     *                      formatted per the International
     *                      SAT competitions format
     * @param pa the parial assignment
     */
    public SubProblem(Formula inputF, Assignment pa)
    {
    	f = inputF;
    	partialAssignment = pa;
    }

    /**
     * Constructor for Subproblem
     *
     * @param a current SubProblem
     *
     */
    public SubProblem (SubProblem s)
    {
    	//f = s.getFormula();
    	//partialAssignment = s.getAssignment();
	f = new Formula (s.getFormula());
    	partialAssignment = new Assignment (s.getAssignment());
    }


    /**
     * Sets the formula
     *
     * @param inputF input file name containg the
     *                      information for the formula;
     *                      formatted per the International
     *                      SAT competitions format
     */
    public void setFormula(Formula inputF)
    {
        f = inputF;
    }

    /**
     * Sets the partial assignment
     *
     * @param pa the partial assignment
     */
    public void setPartialAssignment(Assignment pa)
    {
        partialAssignment = pa;
    }

    /**
     * Rerturns the current formula
     *
     * @return the formula
     */
    public Formula getFormula()
    {
        return f;
    }

    /**
     * Rerturns the current assignment
     *
     * @return the assignment
     */
    public Assignment getAssignment()
    {
        return partialAssignment;
    }

    /**
     * the values of the variables
     * 
     * @return a String with the values of the variables in the subproblem
     */
    public String toString()
    {
        return partialAssignment.toString();
    }
}