/*Knapsack

  This model finds the integer optimal packing of a knapsack

  Nigel_Galloway
  January 9th., 2012
*/

set Items;
param weight{t in Items};
param value{t in Items};

var take{t in Items}, binary;

knap_weight : sum{t in Items} take[t] * weight[t] <= 400;

maximize knap_value: sum{t in Items} take[t] * value[t];

data;

param : Items          : weight   value :=
         map		  9	   150
         compass          13	   35	
         water		  153	   200
         sandwich	  50	   160	
         glucose	  15	   60	
         tin		  68	   45	
         banana		  27	   60	
         apple		  39	   40	
         cheese		  23	   30	
         beer		  52	   10	
         suntancream	  11	   70	
         camera		  32	   30	
         T-shirt	  24	   15	
         trousers	  48	   10	
         umbrella	  73	   40	
         w-trousers	  42	   70	
         w-overclothes	  43	   75	
         note-case	  22	   80	
         sunglasses	  7        20	
         towel		  18	   12	
         socks		  4        50	
         book		  30	   10	
;

end;