private void buildDigraph() throws ContradictionException {
digraph.desactivateNode(n2);
for (int i = 0; i < n2; i++) {
flow[i] = 0;
digraph.getSuccessorsOf(i).clear();
digraph.getPredecessorsOf(i).clear();
}
int j, k, ub;
IntVar v;
for (int i = 0; i < n; i++) {
v = vars[i];
ub = v.getUB();
if (v.instantiated()) {
j = map.get(v.getValue());
if (flow[j] < this.ub[j]) {
digraph.addArc(j, i);
flow[i]++;
flow[j]++;
} else {
contradiction(v, "");
}
} else {
for (k = v.getLB(); k <= ub; k = v.nextValue(k)) {
j = map.get(k);
digraph.addArc(i, j);
}
}
}
}
private void buildSCC() {
digraph.desactivateNode(n2);
digraph.activateNode(n2);
for (int i = n; i < n2; i++) {
if (flow[i] < ub[i]) {
digraph.addArc(i, n2);
}
if (flow[i] > lb[i]) {
digraph.addArc(n2, i);
}
}
SCCfinder.findAllSCC();
nodeSCC = SCCfinder.getNodesSCC();
digraph.desactivateNode(n2);
}
private void useValue(int i) throws ContradictionException {
int mate = swapValue_BFS(i);
if (mate != -1) {
flow[mate]--;
flow[i]++;
int tmp = mate;
while (tmp != i) {
digraph.removeArc(tmp, father[tmp]);
digraph.addArc(father[tmp], tmp);
tmp = father[tmp];
}
} else {
contradiction(null, "no match");
}
}
private void assignVariable(int i) throws ContradictionException {
int mate = augmentPath_BFS(i);
if (mate != -1) {
flow[mate]++;
flow[i]++;
int tmp = mate;
while (tmp != i) {
digraph.removeArc(father[tmp], tmp);
digraph.addArc(tmp, father[tmp]);
tmp = father[tmp];
}
} else {
contradiction(vars[i], "no match");
}
}
private boolean canUnuseValue(int i) {
int mate = augmentPath_BFS(i);
if (mate != -1) {
flow[mate]++;
flow[i]--;
int tmp = mate;
while (tmp != i) {
digraph.removeArc(father[tmp], tmp);
digraph.addArc(tmp, father[tmp]);
tmp = father[tmp];
}
return true;
} else {
return false;
}
}
private int augmentPath_BFS(int root) {
in.clear();
int indexFirst = 0, indexLast = 0;
fifo[indexLast++] = root;
in.set(root); // TODO CORRECTION JG 15/11/12 to test on minizinc instance
int x, y;
ISet succs;
while (indexFirst != indexLast) {
x = fifo[indexFirst++];
succs = digraph.getSuccessorsOf(x);
for (y = succs.getFirstElement(); y >= 0; y = succs.getNextElement()) {
if (!in.get(y)) {
father[y] = x;
fifo[indexLast++] = y;
in.set(y);
if (flow[y] < this.ub[y]) {
if (y < n) {
throw new UnsupportedOperationException();
}
return y;
}
}
}
}
return -1;
}
private int swapValue_BFS(int root) {
in.clear();
int indexFirst = 0, indexLast = 0;
fifo[indexLast++] = root;
in.set(root); // TODO CORRECTION JG 15/11/12 to test on minizinc instance
int x, y;
ISet succs;
while (indexFirst != indexLast) {
x = fifo[indexFirst++];
succs = digraph.getPredecessorsOf(x);
// succs = digraph.getSuccessorsOf(x);
for (y = succs.getFirstElement(); y >= 0; y = succs.getNextElement()) {
if (!in.get(y)) {
father[y] = x;
fifo[indexLast++] = y;
in.set(y);
if (flow[y] > this.lb[y]) {
return y;
}
}
}
}
return -1;
}
private void filter() throws ContradictionException {
buildSCC();
int j, ub;
IntVar v;
for (int i = 0; i < n; i++) {
v = vars[i];
ub = v.getUB();
if (v.getLB() != ub) { // i.e. v is not instantiated
for (int k = v.getLB(); k <= ub; k = v.nextValue(k)) {
j = map.get(k);
if (nodeSCC[i] != nodeSCC[j]) {
if (digraph.arcExists(j, i)) {
v.instantiateTo(k, aCause);
ISet nei = digraph.getSuccessorsOf(i);
for (int s = nei.getFirstElement(); s >= 0; s = nei.getNextElement()) {
digraph.removeArc(i, s);
}
} else {
v.removeValue(k, aCause);
digraph.removeArc(i, j);
}
}
}
}
}
int nb = boundedVariables.size();
for (int i = 0; i < nb; i++) {
v = vars[boundedVariables.get(i)];
ub = v.getUB();
for (int k = v.getLB(); k <= ub; k++) {
j = map.get(k);
if (!(digraph.arcExists(i, j) || digraph.arcExists(j, i))) {
v.removeValue(k, aCause);
}
}
int lb = v.getLB();
for (int k = v.getUB(); k >= lb; k--) {
j = map.get(k);
if (!(digraph.arcExists(i, j) || digraph.arcExists(j, i))) {
v.removeValue(k, aCause);
}
}
}
// filter cardinality variables
int idx;
ISet nei;
for (int i = 0; i < values.length; i++) {
idx = map.get(values[i]);
nei = digraph.getSuccessorsOf(idx);
ub = nei.getSize() + digraph.getPredecessorsOf(idx).getSize();
cards[i].updateUpperBound(ub, aCause);
}
for (int i = 0; i < values.length; i++) {
idx = map.get(values[i]);
int size = digraph.getSuccessorsOf(idx).getSize();
ub = cards[i].getUB();
while (size < ub && canUseValue(idx)) {
size++;
}
cards[i].updateUpperBound(size, aCause);
}
for (int i = 0; i < values.length; i++) {
idx = map.get(values[i]);
while (canUnuseValue(idx)) {}
cards[i].updateLowerBound(digraph.getSuccessorsOf(idx).getSize(), aCause);
}
}