import structure FD from "x-alice:/lib/gecode/FD"
import structure Modeling from "x-alice:/lib/gecode/Modeling"
import structure Explorer from "x-alice:/lib/tools/Explorer"
import structure Space from "x-alice:/lib/gecode/Space"

open Modeling

(* billsandcoins is a vector of pairs where the first component
   specifies the value of a coin in cents and the second the
   the amount of available coins *)
   val billsandcoins = #[{incents=100,avail=6},
  			 {incents=25,avail=8},
  			 {incents=10,avail=10},
  		 	 {incents=5,avail=1},
   			 {incents=1,avail=5}];
                         
(* amount specifies the amount of money you have to pay*)
   val amount = 142;


fun changeMoney(bac:{avail:int,incents:int}vector) amount space =
    let
       val denoms = Vector.map(fn x => 
                     FD.range(space,(0,#avail(x))))(bac)      
    in
       FD.linear(space,VectorPair.zip(Vector.map
                              (fn x =>(#incents(x)))bac,denoms),
                       FD.EQ,amount,FD.DOM);
       FD.branch(space,denoms,FD.B_NONE,FD.B_MAX);
      {dollars=Vector.sub(denoms,0),quarters=Vector.sub(denoms,1),
       dimes=Vector.sub(denoms,2),nickels=Vector.sub(denoms,3),
       pennies=Vector.sub(denoms,4)}
    end    	
 
(* Explorer.exploreAll(changeMoney billsandcoins amount) *);