source: src/main/java/bargainingchips/utilityfunctions/UF_CloseToQuantity.java@ 330

package bargainingchips.utilityfunctions;

import bargainingchips.Bundle;
import bargainingchips.BundleBuilder;
import bargainingchips.Chip;
import bargainingchips.WishList;
import bargainingchips.WishListBuilder;

/**
 * Utility function for testing that acts on queantity alone.
 * Returns 1 when the wish list is exactly satisfied. Becomes lower with higher quantity deviations.
 */
public class UF_CloseToQuantity implements UtilityFunction 
{
        private WishList wishlist;

        public UF_CloseToQuantity(WishList w)
        {
                this.wishlist = w;
        }


        @Override
        public Double getUtility(Bundle b) 
        {
                int totalDeviation = 0;
                for (Chip c : wishlist)
                {
                        int desired = wishlist.getQuantity(c);
                        Integer offered = b.getQuantity(c);
                        if (offered == null)
                                offered = 0;

                        int deviationOffered = Math.abs(desired - offered);
                        totalDeviation += deviationOffered;
                }

                return 1.0 / (1 + totalDeviation);
        }

        @Override
        public String toString()
        {
                return this.getClass().getSimpleName() + ": " + wishlist.toString();
        }
        
        public static void main(String[] args) 
        {
                WishList wishlist = new WishListBuilder().addWish("Red", 7).addWish("Green", 5).build();
                UF_CloseToQuantity u = new UF_CloseToQuantity(wishlist);
                System.out.println(u);
                
                Bundle offer = new BundleBuilder()
                                .addStack("Red", 1.0, 6)
                                .addStack("Green", 3.0, 15)
                                .addStack("Purple", 0.10, 10)
                                .build();
                System.out.println(u.getUtility(offer));
        }

}