def enumerate(
self
): # Branch and Bound on variables. Depth-first search. With exception.
x = self.nextVar()
if x:
v = x.inf
store.push()
try:
assert (Logprint.logPrint(2,
"==> Try {} = {}".format(x.name,
v)) == None)
x.isEQ(v)
self.enumerate()
except filter.FAIL:
store.back()
self.NBbk += 1
x.isGE(v + filter.UN)
self.enforceBB()
self.enumerate()
else:
store.back()
else:
self.NBsol += 1
assert (Logprint.logPrint(
2, "<=====****===== Found solution n°{} in {} backtracks{}".
format(
self.NBsol, self.NBbk, " at {}={}".format(
self.OBJECTIVE.name, self.OBJECTIVE.inf
if self.MINI else self.OBJECTIVE.sup)
if self.OBJECTIVE else "")) == None)
self.saveSolution()
self.Bound = self.newBound()
self.NBbkTot += self.NBbk
self.NBbk = 0
if self.ALLSOL: raise filter.FAIL
def validate(vars, sol): # vars is a list, sol is a dicho
store.push()
try:
for v in vars:
v.isEQ(sol[v.name])
except filter.FAIL as e:
Logprint.logPrint(2, e)
Logprint.logPrint(1, "The solution is not valid:")
showVar(sol)
store.back()
return False
Logprint.logPrint(1, "The solution is valid")
store.back()
return True
def solve(self):
store.push()
try:
while True:
assert (Logprint.logPrint(
2, "======****====> Looking for a solution {}".format(
"at {}={}".format(self.OBJECTIVE.name, self.Bound)
if self.OBJECTIVE else "")) == None)
self.enforceBound()
if self.SEARCH == 0: self.search()
elif self.SEARCH == 1: pass
elif self.SEARCH == 2: self.enumerate()
elif self.SEARCH == 3: self.dicho()
else: pass
if not self.OBJECTIVE: raise filter.FAIL
except filter.FAIL:
pass
store.back()
if self.OBJECTIVE:
Logprint.logPrint(
2, "<=====****===== Optimum proved in {} backtracks".format(
self.NBbk))
return True
def dicho(
self
): # Branch and Bound on variables. Dichotomic search. With exception.
x = self.nextVar()
if x:
mid = (x.inf + x.sup) // filter.DEUX
store.push()
try:
assert (Logprint.logPrint(
2, "==> Try {} <= {}".format(x.name, mid)) == None)
x.isLE(mid)
self.dicho()
except filter.FAIL:
store.back()
self.NBbk += 1
self.enforceBB()
store.push()
try:
assert (Logprint.logPrint(
2, "==> Try {} > {}".format(x.name, mid)) == None)
x.isGE(mid + filter.UN)
self.dicho()
except filter.FAIL:
store.back()
self.NBbk += 1
raise filter.FAIL
else:
store.back()
else:
store.back()
else:
self.NBsol += 1
assert (Logprint.logPrint(
2, "<=====****===== Found solution n°{} in {} backtracks{}".
format(
self.NBsol, self.NBbk, " at {}={}".format(
self.OBJECTIVE.name, self.OBJECTIVE.inf
if self.MINI else self.OBJECTIVE.sup)
if self.OBJECTIVE else "")) == None)
self.saveSolution()
self.Bound = self.newBound()
self.NBbkTot += self.NBbk
self.NBbk = 0
if self.ALLSOL: raise filter.FAIL
def search(self): # Branch and Bound on disjunctions with exception.
d = self.nextDisjunction()
if d:
left = self.leftFirst(d)
store.push()
try:
d.settled(left)
self.search()
except filter.FAIL:
store.back()
self.NBbk += 1
self.enforceBB()
store.push()
try:
d.settled(not (left))
self.search()
except filter.FAIL:
store.back()
self.NBbk += 1
raise filter.FAIL
else:
store.back()
else:
store.back()
else:
self.NBsol += 1
assert (Logprint.logPrint(
2, "<=====****===== Found solution n°{} in {} backtracks{}".
format(
self.NBsol, self.NBbk, " at {}={}".format(
self.OBJECTIVE.name, self.OBJECTIVE.inf
if self.MINI else self.OBJECTIVE.sup)
if self.OBJECTIVE else "")) == None)
self.saveSolution()
self.Bound = self.newBound()
self.NBbkTot += self.NBbk
self.NBbk = 0
if self.ALLSOL: raise filter.FAIL