//package GregDLLSolver;

//Author:Greg Viola
//Class: Algos
//Version: 3
//Due Date: 4/10/07
//Status: Complete up to specifications

import java.util.*;

/**
* Stores a vector of integers.  These integers correspond
* to variable assignments.
*/
public class Assignment
{
 private Vector <Integer> values;



/**
 * Constructs an assignment of uninitialized variables.
 *
 * @param numVars the number of variables.
 */
 public Assignment(int numVars)
 {
      values = new Vector <Integer> (numVars);
      for (int i=0; i<numVars; i++)
      {
         values.addElement(-1);//Initially unassigned variables
      }
}


/**
 * Constructs a clone of a.
 *
 * @param a another assignment.
 */
 public Assignment(Assignment a)
 {
      values = new Vector <Integer> (a.getValues());
 }





/**
 * Assigns a variable to true(1), false(0), or unassigned(-1).
 *
 * @param var the variable to be assigned.
 * @param set the integer that the variable will be assigned
 */
 public void assignVar(int var, int set)
 {
      values.setElementAt(set,var-1);
 }



/**
 * Returns the assignment vector.
 *
 * @return Vector of values (1, 0, or -1) assigned to the variables.
 */
 protected Vector getValues()
 {
      return values;
 }



 // !!!!!!!! DEE !!!!!!!!!!!!!!!!
/**
 * Returns the assignment vector.
 *
 * @return Vector the list of integers.
 */
 public Vector getAssignment()
 {
      return values;
 }

 // !!!!!!!! DEE !!!!!!!!!!!!!!!!
 public int getValue( int i)
 {
     return values.get(i);
 } 

 // !!!!!!!! DEE !!!!!!!!!!!!!!!!
 public int findFirstUnassignedVar()
 {
     int assign = -1; //Used to extract each assignment
     //This loop used to list all assignments.
     for (int i=0; i<values.size()-1; i++)
     {
	assign = values.get(i);
	if (assign == -1)
	  return i;
     }
     return -1;
 }

 // !!!!!!!! DEE !!!!!!!!!!!!!!!!
 public boolean getNumUnassignedVars()
 {
     int assign = -1; //Used to extract each assignment
     //This loop used to list all assignments.
     for (int i=0; i<values.size()-1; i++)
     {
        assign = values.get(i);
	if (assign == -1)
 	    return true;
     }
     return false;

 }
/**
 * Prints out the assignment as a string.
 *
 * @return String the assignment as a string.
 */
 public String toString()
 {
      String result = "";

      /*
      result += "(";
      //This loop used to list all of the variables
      for (int i=1; i<=values.size()-1; i++)
      {
         result += "x" + i + ",";
      }
      result += "x" + values.size() + ") = (";
      */

      int assign = -1; //Used to extract each assignment

      //This loop used to "list" all-but-the-last value.
      for (int i=0; i<values.size()-1; i++)
      {
         assign = values.get(i);

         if (assign == 1)
         {
            result += "T,";
         }
         if (assign == 0)
         {
            result += "F,";
         }
         if (assign == -1)
         {
            result += "_,";
         }
      }

      // "list" the last value
      assign = values.get(values.size()-1);
      if (assign == 1)
      {
         result += "T)";
      }
      if (assign == 0)
      {
         result += "F)";
      }
      if (assign == -1)
      {
          result += "_)";
      }

      return result;
 }//end toString

}//end Assignment