RosettaCodeData/Task/Knapsack-problem-Unbounded/Forth/knapsack-problem-unbounded-2.fth

0 VALUE vials
0 VALUE ampules
0 VALUE bars
0 VALUE bag

#250   3 /  #250 #25 /   MIN 1+ CONSTANT maxvials
#250    2/  #250 #15 /   MIN 1+ CONSTANT maxampules
#250 #20 /  #250    2/   MIN 1+ CONSTANT maxbars

: RESULTS ( v a b -- k )
   3DUP #20 *  SWAP 2*      +  SWAP     3 * +  #250 > IF  3DROP -1 EXIT  ENDIF
   3DUP    2*  SWAP #15   * +  SWAP   #25 * +  #250 > IF  3DROP -1 EXIT  ENDIF
   #2500    *  SWAP #1800 * +  SWAP #3000 * + ;

: .SOLUTION ( -- )
   CR ." The traveller's knapsack contains "
      vials   DEC. ." vials of panacea, "
      ampules DEC. ." ampules of ichor, "
   CR bars    DEC. ." bars of gold, a total value of "
      vials ampules bars RESULTS 0DEC.R ." ." ;

: KNAPSACK ( -- )
   -1 TO bag
   maxvials 0 ?DO
   maxampules 0 ?DO
        maxbars 0 ?DO
                              K J I RESULTS DUP
             bag  > IF  TO bag  K TO vials J TO ampules I TO bars
            ELSE  DROP
                 ENDIF
           LOOP
         LOOP
       LOOP
   .SOLUTION ;