inline ExecStatus
Prop<View>::post(Home home, ViewArray<View>& x, View y) {
if (x.size() == 0)
return ES_FAILED;
x.unique(home);
if (x.size() == 1)
return Rel::EqDom<View,View>::post(home,x[0],y);
if (x.same(home,y))
return ES_OK;
// Eliminate assigned views and store them into the value set
ValSet vs;
add(home, vs, x);
if (x.size() == 0) {
ValSet::Ranges vsr(vs);
GECODE_ME_CHECK(y.inter_r(home,vsr,false));
return ES_OK;
}
(void) new (home) Prop<View>(home, vs, x, y);
return ES_OK;
}
ExecStatus
IntBase<VY>::all_in_valset(Space& home) {
for (int i=x.size(); i--; ) {
ValSet::Ranges vsr(vs);
GECODE_ME_CHECK(x[i].inter_r(home, vsr, false));
}
return home.ES_SUBSUMED(*this);
}
forceinline bool
ValSet::subset(View x) const {
if (empty() || (x.min() < min()) || (x.max() > max()))
return false;
ValSet::Ranges vsr(*this);
ViewRanges<View> xr(x);
return Iter::Ranges::subset(xr,vsr);
}
forceinline Iter::Ranges::CompareStatus
ValSet::compare(View x) const {
if (empty() || (x.max() < min()) || (x.min() > max()))
return Iter::Ranges::CS_DISJOINT;
ValSet::Ranges vsr(*this);
ViewRanges<View> xr(x);
return Iter::Ranges::compare(xr,vsr);
}
ExecStatus
Prop<View>::propagate(Space& home, const ModEventDelta& med) {
// Add assigned views to value set
if (View::me(med) == ME_INT_VAL)
add(home,vs,x);
// Eliminate views from x
eliminate(home);
if (x.size() == 0) {
// y must have values in the value set
ValSet::Ranges vsr(vs);
GECODE_ME_CHECK(y.inter_r(home,vsr,false));
return home.ES_SUBSUMED(*this);
}
// Constrain y to union of x and value set
Region r(home);
assert(x.size() > 0);
ValSet::Ranges vsr(vs);
ViewRanges<View> xsr(x[x.size()-1]);
Iter::Ranges::NaryUnion u(r,vsr,xsr);
for (int i=x.size()-1; i--; ) {
ViewRanges<View> xir(x[i]);
u |= xir;
}
GECODE_ME_CHECK(y.inter_r(home,u,false));
// Check whether all values in y are already in the value set
if (vs.subset(y))
return home.ES_SUBSUMED(*this);
return ES_FIX;
}
int
IntBase<VY>::size(Space& home) const {
Region r(home);
assert(x.size() > 0);
ValSet::Ranges vsr(vs);
ViewRanges<IntView> xr(x[x.size()-1]);
Iter::Ranges::NaryUnion u(r,vsr,xr);
for (int i=x.size()-1; i--; ) {
ViewRanges<IntView> xir(x[i]);
u |= xir;
}
unsigned int s = Iter::Ranges::size(u);
// To avoid overflow
if (static_cast<unsigned int>(x.size()+vs.size()) < s)
return x.size() + vs.size();
else
return static_cast<int>(s);
}
forceinline ExecStatus
IntBase<VY>::prune_upper(Space& home, Graph& g) {
if (!g.initialized()) {
g.init(home,vs,x);
} else {
g.purge();
g.sync(home);
}
GECODE_ME_CHECK(y.lq(home, g.size()));
if (y.min() == g.size()) {
// All values must be taken on
if (vs.size() + x.size() == g.size()) {
// This is in fact a distinct, simplify and rewrite
for (int i=x.size(); i--; ) {
ValSet::Ranges vsr(vs);
GECODE_ME_CHECK(x[i].minus_r(home, vsr, false));
}
GECODE_REWRITE(*this,Distinct::Dom<IntView>::post(home,x));
}
if (g.mark(home))
GECODE_ES_CHECK(g.prune(home));
}
return ES_OK;
}
ExecStatus
IntBase<VY>::prune_lower(Space& home, int* dis, int n_dis) {
assert(n_dis > 0);
// At least one more value will be needed
GECODE_ME_CHECK(y.gq(home,vs.size() + 1));
Region r(home);
// Only one additional value is allowed
if (y.max() == vs.size() + 1) {
// Compute possible values
ViewRanges<IntView>* r_dis = r.alloc<ViewRanges<IntView> >(n_dis);
for (int i=n_dis; i--; )
r_dis[i] = ViewRanges<IntView>(x[dis[i]]);
Iter::Ranges::NaryInter iv(r, r_dis, n_dis);
// Is there a common value at all?
if (!iv())
return ES_FAILED;
ValSet::Ranges vsr(vs);
Iter::Ranges::NaryUnion pv(r,iv,vsr);
// Enforce common values
for (int i=x.size(); i--; ) {
pv.reset();
GECODE_ME_CHECK(x[i].inter_r(home, pv, false));
}
return ES_OK;
}
// Compute independent set for lower bound
// ovl is a bit-matrix defining whether two views overlap
SymBitMatrix ovl(r,x.size());
// deg[i] is the degree of x[i]
int* deg = r.alloc<int>(x.size());
// ovl_i[i] is an array of indices j such that x[j] overlaps with x[i]
int** ovl_i = r.alloc<int*>(x.size());
// n_ovl_i[i] defines how many integers are stored for ovl_i[i]
int* n_ovl_i = r.alloc<int>(x.size());
{
#ifndef NDEBUG
// Initialize all to null pointers so that things crash ;-)
for (int i=x.size(); i--; )
ovl_i[i] = NULL;
#endif
// For each i there can be at most n_dis-1 entries in ovl_i[i]
int* m = r.alloc<int>(n_dis*(n_dis-1));
for (int i=n_dis; i--; ) {
deg[dis[i]] = 0;
ovl_i[dis[i]] = m; m += n_dis-1;
}
}
// Initialize overlap matrix by analyzing the view ranges
{
// Compute how many events are needed
// One event for the end marker
int n_re = 1;
// Two events for each range
for (int i=n_dis; i--; )
for (ViewRanges<IntView> rx(x[dis[i]]); rx(); ++rx)
n_re += 2;
// Allocate and initialize events
RangeEvent* re = r.alloc<RangeEvent>(n_re);
int j=0;
for (int i=n_dis; i--; )
for (ViewRanges<IntView> rx(x[dis[i]]); rx(); ++rx) {
// Event when a range starts
re[j].ret=RET_FST; re[j].val=rx.min(); re[j].view=dis[i]; j++;
// Event when a range ends
re[j].ret=RET_LST; re[j].val=rx.max(); re[j].view=dis[i]; j++;
}
// Make this the last event
re[j].ret=RET_END; re[j].val=Int::Limits::infinity;
assert(j+1 == n_re);
// Sort and process events
Support::quicksort(re,n_re);
// Current views with a range being active
Support::BitSet<Region> cur(r,static_cast<unsigned int>(x.size()));
// Process all events
for (int i=0; true; i++)
switch (re[i].ret) {
case RET_FST:
// Process all overlapping views
for (Iter::Values::BitSet<Support::BitSet<Region> > j(cur);
j(); ++j) {
int di = re[i].view, dj = j.val();
if (!ovl.get(di,dj)) {
ovl.set(di,dj);
ovl_i[di][deg[di]++] = dj;
ovl_i[dj][deg[dj]++] = di;
}
}
cur.set(static_cast<unsigned int>(re[i].view));
break;
case RET_LST:
cur.clear(static_cast<unsigned int>(re[i].view));
break;
case RET_END:
goto done;
default:
GECODE_NEVER;
}
done:
r.free<RangeEvent>(re,n_re);
}
// While deg changes, n_ovl_i remains unchanged and is needed, so copy it
for (int i=n_dis; i--; ) {
assert(deg[dis[i]] < n_dis);
n_ovl_i[dis[i]] = deg[dis[i]];
}
// Views in the independent set
int* ind = r.alloc<int>(n_dis);
int n_ind = 0;
while (n_dis > 0) {
int i_min = n_dis-1;
int d_min = deg[dis[i_min]];
unsigned int s_min = x[dis[i_min]].size();
// Find view with smallest (degree,size)
for (int i=n_dis-1; i--; )
if ((d_min > deg[dis[i]]) ||
((d_min == deg[dis[i]]) && (s_min > x[dis[i]].size()))) {
i_min = i;
d_min = deg[dis[i]];
s_min = x[dis[i]].size();
}
// i_min refers to view with smallest (degree,size)
ind[n_ind++] = dis[i_min]; dis[i_min] = dis[--n_dis];
// Filter out non disjoint views
for (int i=n_dis; i--; )
if (ovl.get(dis[i],ind[n_ind-1])) {
// Update degree information
for (int j=n_ovl_i[dis[i]]; j--; )
deg[ovl_i[dis[i]][j]]--;
// Eliminate view
dis[i] = dis[--n_dis];
}
}
// Enforce lower bound
GECODE_ME_CHECK(y.gq(home,vs.size() + n_ind));
// Prune, if possible
if (vs.size() + n_ind == y.max()) {
// Only values from the indepent set a can be taken
ViewRanges<IntView>* r_ind = r.alloc<ViewRanges<IntView> >(n_ind);
for (int i=n_ind; i--; )
r_ind[i] = ViewRanges<IntView>(x[ind[i]]);
Iter::Ranges::NaryUnion v_ind(r, r_ind, n_ind);
ValSet::Ranges vsr(vs);
v_ind |= vsr;
for (int i=x.size(); i--; ) {
v_ind.reset();
GECODE_ME_CHECK(x[i].inter_r(home,v_ind,false));
}
}
return ES_OK;
}
ExecStatus
ReProp<View,rm>::propagate(Space& home, const ModEventDelta& med) {
// Add assigned views to value set
if (View::me(med) == ME_INT_VAL)
add(home,vs,x);
if (b.one()) {
if (rm == RM_PMI)
return home.ES_SUBSUMED(*this);
ValSet vsc(vs);
vs.flush();
GECODE_REWRITE(*this,Prop<View>::post(home,vsc,x,y));
}
if (b.zero()) {
if (rm != RM_IMP) {
ValSet::Ranges vsr(vs);
GECODE_ME_CHECK(y.minus_r(home,vsr,false));
for (int i=x.size(); i--; )
GECODE_ES_CHECK(Rel::Nq<View>::post(home,x[i],y));
}
return home.ES_SUBSUMED(*this);
}
// Eliminate views from x
eliminate(home);
switch (vs.compare(y)) {
case Iter::Ranges::CS_SUBSET:
if (rm != RM_IMP)
GECODE_ME_CHECK(b.one(home));
return home.ES_SUBSUMED(*this);
case Iter::Ranges::CS_DISJOINT:
if (x.size() == 0) {
if (rm != RM_PMI)
GECODE_ME_CHECK(b.zero(home));
return home.ES_SUBSUMED(*this);
}
break;
case Iter::Ranges::CS_NONE:
break;
default:
GECODE_NEVER;
}
// Check whether y is in union of x and value set
if (x.size() > 0) {
Region r(home);
ValSet::Ranges vsr(vs);
ViewRanges<View> xsr(x[x.size()-1]);
Iter::Ranges::NaryUnion u(r,vsr,xsr);
for (int i=x.size()-1; i--; ) {
ViewRanges<View> xir(x[i]);
u |= xir;
}
ViewRanges<View> yr(y);
if (Iter::Ranges::disjoint(u,yr)) {
if (rm != RM_PMI)
GECODE_ME_CHECK(b.zero(home));
return home.ES_SUBSUMED(*this);
}
}
return ES_FIX;
}
