/*
*
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*
* Unless required by applicable law or agreed to in writing, software
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
*/

/*  Fractions problem with JaCoP.
Find distinct non-zero digits such that the following equation holds:
A        D        G
------  + ----- + ------  = 1
B*C      E*F      H*I

Created as an assignment for Advanced Artificial Intelligence graduate class of 2016 (http://www.di.uoa.gr/eng/node/1449)
*/

import org.jacop.constraints.Alldifferent;
import org.jacop.constraints.Constraint;
import org.jacop.constraints.SumWeight;
import org.jacop.constraints.XgtY;
import org.jacop.constraints.XmulYeqZ;
import org.jacop.constraints.XplusYplusQeqZ;
import org.jacop.core.IntVar;
import org.jacop.core.Store;
import org.jacop.search.DepthFirstSearch;
import org.jacop.search.IndomainMin;
import org.jacop.search.InputOrderSelect;
import org.jacop.search.PrintOutListener;
import org.jacop.search.Search;
import org.jacop.search.SelectChoicePoint;

public class fractions_JaCoP {
public static void main (String[] args) {
Store store = new Store();  // define FD store

// define finite domain variables
IntVar A = new IntVar(store, "A", 1, 9);
IntVar B = new IntVar(store, "B", 1, 9);
IntVar C = new IntVar(store, "C", 1, 9);
IntVar D = new IntVar(store, "D", 1, 9);
IntVar E = new IntVar(store, "E", 1, 9);
IntVar F = new IntVar(store, "F", 1, 9);
IntVar G = new IntVar(store, "G", 1, 9);
IntVar H = new IntVar(store, "H", 1, 9);
IntVar I = new IntVar(store, "I", 1, 9);

//A,B,C,D,E,F,G,H,I all different
IntVar[] digits = {A,B,C,D,E,F,G,H,I};
IntVar[] v1 = {B, C};
IntVar[] v2 = {E, F};
IntVar[] v3 = {H, I};

Constraint ctr = new Alldifferent(digits);
store.impose(ctr);

//10*B+C,10*E+F,10*H+I
IntVar value_BC = new IntVar(store, "D1", 0, 81);
IntVar value_EF = new IntVar(store, "D2", 0, 81);
IntVar value_HI = new IntVar(store, "D3", 0, 81);

int[] weights = { 10, 1 };
store.impose(new SumWeight (v1, weights, value_BC));
store.impose(new SumWeight (v2, weights, value_EF));
store.impose(new SumWeight (v3, weights, value_HI));

//BC*EF,HI*BC,BC*EF
IntVar value_BCEF = new IntVar(store, "D1-2", 0, 6561);
IntVar value_EFHI = new IntVar(store, "D2-3", 0, 6561);
IntVar value_HIBC = new IntVar(store, "D1-3", 0, 6561);

store.impose(new XmulYeqZ(value_BC, value_EF, value_BCEF));
store.impose(new XmulYeqZ(value_EF, value_HI, value_EFHI));
store.impose(new XmulYeqZ(value_HI, value_BC, value_HIBC));

//HI*BC*EF
IntVar value_BCEFHI = new IntVar(store, "D1-2-3", 0, 531441);
store.impose(new XmulYeqZ(value_HIBC, value_EF, value_BCEFHI));

//A*EF*HI,D*HI*BC,G*BC*EF
IntVar value_AEFHI = new IntVar(store, "A2-3", 0, 531441);
IntVar value_DHIBC = new IntVar(store, "B1-3", 0, 531441);
IntVar value_GBCEF = new IntVar(store, "C1-2", 0, 531441);

store.impose(new XmulYeqZ(A, value_EFHI, value_AEFHI));
store.impose(new XmulYeqZ(D, value_HIBC, value_DHIBC));
store.impose(new XmulYeqZ(G, value_BCEF, value_GBCEF));

//(A*EF*HI)+(D*HI*BC)+(G*BC*EF)=(EF*HI*BC)
store.impose(new XplusYplusQeqZ(value_AEFHI, value_DHIBC, value_GBCEF,value_BCEFHI));

//Break symetries
store.impose(new XgtY(G, D));
store.impose(new XgtY(D, A));

// search for a solution and print results
Search<IntVar> search = new DepthFirstSearch<>();
SelectChoicePoint<IntVar> select = new InputOrderSelect<>(store, digits, new IndomainMin<>());
search.setSolutionListener(new PrintOutListener<>());
search.getSolutionListener().searchAll(true);
search.labeling(store, select);
}
}