public class Knapsack_unbounded
{

    /* ========================================================
       M(j) = max value achieved by knapsack with capacity j
       ======================================================== */
    static int M(int[] v, int[] w, int j)
    {
       int sol, my_sol;
       int k, max;


       /* ---------------------------
	  Base cases
	  --------------------------- */
       if ( j == 0 )
       {
	   return(0);
       }

       max = 0;			// No items in knapsack

       for ( k = 0; k < v.length; k++ )
       {
          /* --------------------------------------------
	     Check if we can use the k-th type item
	     -------------------------------------------- */
          if ( w[k] <= j )
          {
             /* ------------------------
	        Divide step
	        ------------------------ */
             sol = M(v, w, j - w[k]);    // Try item of type k
				         // with weight w[k]

	     /* ---------------------------------------
	        Conquer: solve original problem using
	        solution from smaller problems
	        --------------------------------------- */
	     my_sol = sol + v[k];       // See class notes

	     /* ---------------------------------------
	        Determine the best (last) item to use
	        --------------------------------------- */
	     if ( my_sol > max )
	        max = my_sol;	       // A better solution found
          }
       }

       return(max);   // Return the overal best solution
   }


   public static void main(String[] args)
   {
       int[] v = {1, 2, 3, 5, 6, 8};
       int[] w = {2, 3, 5, 8, 9, 13};

       int C, r;

       C = 18;                  // Around 53 it starts to slow...
       r = M(v, w, C);

       System.out.println("Max value packed in backpack of capacity " 
				+ C + " = " + r);
   }

}