ExecStatus
LqInt<VX,VY>::post(Home home, ViewArray<VX>& x, VY y, int c) {
// Eliminate decided views
int n_x = x.size();
for (int i=n_x; i--; )
switch (holds(x[i],y)) {
case RT_FALSE:
x[i] = x[--n_x]; break;
case RT_TRUE:
x[i] = x[--n_x]; c--; break;
case RT_MAYBE:
break;
default:
GECODE_NEVER;
}
x.size(n_x);
if (c < 0)
return ES_FAILED;
if (c >= n_x)
return ES_OK;
// All views must be different
if (c == 0)
return post_false(home,x,y);
(void) new (home) LqInt<VX,VY>(home,x,n_x-c+1,y,c);
return ES_OK;
}
ExecStatus
EqInt<VX,VY>::post(Home home, ViewArray<VX>& x, VY y, int c) {
// Eliminate decided views
int n_x = x.size();
for (int i=n_x; i--; )
switch (holds(x[i],y)) {
case RT_FALSE:
x[i] = x[--n_x]; break;
case RT_TRUE:
x[i] = x[--n_x]; c--; break;
case RT_MAYBE:
break;
default:
GECODE_NEVER;
}
x.size(n_x);
// RHS too small or too large
if ((c < 0) || (c > n_x))
return ES_FAILED;
// All views must be different
if (c == 0)
return post_false(home,x,y);
// All views must be equal
if (c == n_x)
return post_true(home,x,y);
// Compute how many subscriptions must be created
int n_s = std::max(c,n_x-c)+1;
assert(n_s <= n_x);
(void) new (home) EqInt<VX,VY>(home,x,n_s,y,c);
return ES_OK;
}
ExecStatus
EqInt<VX,VY>::propagate(Space& home, const ModEventDelta&) {
// Eliminate decided views from subscribed views
int n_x = x.size();
for (int i=n_s; i--; )
switch (holds(x[i],y)) {
case RT_FALSE:
x[i].cancel(home,*this,PC_INT_DOM);
x[i]=x[--n_s]; x[n_s]=x[--n_x];
break;
case RT_TRUE:
x[i].cancel(home,*this,PC_INT_DOM);
x[i]=x[--n_s]; x[n_s]=x[--n_x]; c--;
break;
case RT_MAYBE:
break;
default:
GECODE_NEVER;
}
x.size(n_x);
if ((c < 0) || (c > n_x))
return ES_FAILED;
// Eliminate decided views from unsubscribed views
for (int i=n_x; i-- > n_s; )
switch (holds(x[i],y)) {
case RT_FALSE: x[i]=x[--n_x]; break;
case RT_TRUE: x[i]=x[--n_x]; c--; break;
case RT_MAYBE: break;
default: GECODE_NEVER;
}
x.size(n_x);
if ((c < 0) || (c > n_x))
return ES_FAILED;
if (c == 0) {
// All views must be different
GECODE_ES_CHECK(post_false(home,x,y));
return home.ES_SUBSUMED(*this);
}
if (c == n_x) {
// All views must be equal
GECODE_ES_CHECK(post_true(home,x,y));
return home.ES_SUBSUMED(*this);
}
int m = std::max(c,n_x-c)+1;
assert(m <= n_x);
// Now, there must be new subscriptions from x[n_s] up to x[m-1]
while (n_s < m)
x[n_s++].subscribe(home,*this,PC_INT_DOM,false);
return ES_FIX;
}
ExecStatus
LqView<VX,VY,VZ,shr>::propagate(Space& home, const ModEventDelta&) {
count(home);
GECODE_ME_CHECK(z.gq(home,atleast()));
if (z.max() == atleast()) {
GECODE_ES_CHECK(post_false(home,x,y));
return home.ES_SUBSUMED(*this);
}
if (x.size() == 0)
return home.ES_SUBSUMED(*this);
if (z.assigned()) {
VY yc(y);
GECODE_REWRITE(*this,(LqInt<VX,VY>::post(home(*this),x,yc,z.val()+c)));
}
return shr ? ES_NOFIX : ES_FIX;
}
ExecStatus
EqView<VX,VY,VZ,shr,dom>::propagate(Space& home, const ModEventDelta&) {
count(home);
GECODE_ME_CHECK(z.gq(home,atleast()));
GECODE_ME_CHECK(z.lq(home,atmost()));
if (z.assigned()) {
if (z.val() == atleast()) {
GECODE_ES_CHECK(post_false(home,x,y));
return home.ES_SUBSUMED(*this);
}
if (z.val() == atmost()) {
GECODE_ES_CHECK(post_true(home,x,y));
return home.ES_SUBSUMED(*this);
}
if (!dom || (vtd(y) != VTD_VARVIEW)) {
VY yc(y);
GECODE_REWRITE(*this,(EqInt<VX,VY>
::post(home(*this),x,yc,z.val()+c)));
}
}
if (dom && (vtd(y) == VTD_VARVIEW) && (z.min() > 0)) {
/*
* Only if the propagator is at fixpoint here, continue
* when things are shared: the reason is that prune
* requires that the views in x overlap with y!
*/
if (shr && (VX::me(Propagator::modeventdelta()) != ME_INT_NONE))
return ES_NOFIX;
GECODE_ES_CHECK(prune(home,x,y));
return ES_NOFIX;
}
return shr ? ES_NOFIX : ES_FIX;
}
