示例#1
0
 def solve(self):
     """
     Searches for a solution using a combination of arcConsistency
     and backtracking. The Algorithm will run arcConsistency,
     find the smallest remaining domain (that's greater than 1), and
     systematically assign a value to the variable and recurse onwards.
     Returns True if a solution is found, False otherwise.
     """
     self.arcConsistencyHelper()
     if self.isSolved():
         for coordinate in self.board.getCoordinates():
             coordinate.setValue(coordinate.getDomain()[0])
         return True
     elif self.isDeadEnd():
         return False
     else:
         print("selecting a variable to assign")
         savedDomains = self.backupDomains(self.getListOfDomains())
         smallest = self.indexOfSmallestDomain(savedDomains)
         for x in savedDomains[smallest]:
             self.addRelatedToQueue(self.coordinates[smallest])
             self.coordinates[smallest].setDomain([x,])
             if (self.solve()):
                 return True
             self.restoreDomains(self.backupDomains(savedDomains))
         else:
             return False
示例#2
0
 def solve(self):
     """
     Searches for a solution using a combination of arcConsistency
     and backtracking. The Algorithm will run arcConsistency,
     find the smallest remaining domain (that's greater than 1), and
     systematically assign a value to the variable and recurse onwards.
     Returns True is a solution is found, False otherwise.
     """
     self.arcConsistencyHelper()
     if self.isSolved():
         for coordinate in self.board.getCoordinates():
             coordinate.setValue(coordinate.getDomain()[0])
         return True
     elif self.isDeadEnd():
         return False
     else:
         print("selecting a variable to assign")
         savedDomains = self.backupDomains(self.getListOfDomains())
         smallest = self.indexOfSmallestDomain(savedDomains)
         for x in savedDomains[smallest]:
             self.addRelatedToQueue(self.coordinates[smallest])
             self.coordinates[smallest].setDomain([
                 x,
             ])
             if (self.solve()):
                 return True
             self.restoreDomains(self.backupDomains(savedDomains))
         else:
             return False
示例#3
0
 def solveWithLCV(self):
     """
     Works the same as solveWithBackTracking, but assigns the variable
     in an order such that you assign the least constraining value first.  
     That is, assign the value which would cause the least domain pruning 
     after running arcConsistency.
     """
     self.arcConsistencyHelper()
     if self.isSolved():
         for coordinate in self.board.getCoordinates():
             coordinate.setValue(coordinate.getDomain()[0])
         return True
     elif self.isDeadEnd():
         return False
     else:
         savedDomains = self.backupDomains(self.getListOfDomains())
         smallest = self.indexOfSmallestDomain(savedDomains)
         resultingDomainsList = []
         for x in savedDomains[smallest]:
             self.addRelatedToQueue(self.coordinates[smallest])
             self.coordinates[smallest].setDomain([
                 x,
             ])
             self.arcConsistencyHelper()
             resultingDomainsList.append((x, self.getListOfDomains()))
             self.restoreDomains(self.backupDomains(savedDomains))
         for assignment, resultingDomains in resultingDomainsList:
             for domain in resultingDomains:
                 if (len(domain) == 0):
                     resultingDomainsList.remove(
                         (assignment,
                          resultingDomains))  #This assignment cannot work
                     break
         #compute resulting total domain sizes
         mappedTotalDomainSizes = list(
             map(self.totalSizeOfDomains,
                 [domains for assignment, domains in resultingDomainsList]))
         #pick the assigned variables, ordered by resulting domain size
         for i in range(len(resultingDomainsList)):
             currentAssignmentIndex = mappedTotalDomainSizes.index(
                 max(mappedTotalDomainSizes))
             currentAssignment, currentDomains = resultingDomainsList[
                 currentAssignmentIndex]
             self.restoreDomains(currentDomains)
             self.coordinates[smallest].setDomain([
                 currentAssignment,
             ])
             if (self.solveWithLCV()):
                 return True
         else:
             return False
示例#4
0
 def solveWithLCV(self):
     """
     Works the same as solveWithBackTracking, but assigns the variable
     in an order such that you assign the least constraining value first.
     That is, assign the value which would cause the least domain pruning
     after running arcConsistency.
     """
     self.arcConsistencyHelper()
     if self.isSolved():
         for coordinate in self.board.getCoordinates():
             coordinate.setValue(coordinate.getDomain()[0])
         return True
     elif self.isDeadEnd():
         return False
     else:
         savedDomains = self.backupDomains(self.getListOfDomains())
         smallest = self.indexOfSmallestDomain(savedDomains)
         resultingDomainsList = []
         for x in savedDomains[smallest]:
             self.addRelatedToQueue(self.coordinates[smallest])
             self.coordinates[smallest].setDomain([x,])
             self.arcConsistencyHelper()
             resultingDomainsList.append((x, self.getListOfDomains()))
             self.restoreDomains(self.backupDomains(savedDomains))
         for assignment, resultingDomains in resultingDomainsList:
             for domain in resultingDomains:
                 if (len(domain) == 0):
                     resultingDomainsList.remove((assignment, resultingDomains)) #This assignment cannot work
                     break
         #compute resulting total domain sizes
         mappedTotalDomainSizes = list(map(self.totalSizeOfDomains,
                                             [domains for assignment, domains in resultingDomainsList]))
         #pick the assigned variables, ordered by resulting domain size
         for i in range(len(resultingDomainsList)):
             currentAssignmentIndex = mappedTotalDomainSizes.index(max(mappedTotalDomainSizes))
             currentAssignment, currentDomains = resultingDomainsList[currentAssignmentIndex]
             self.restoreDomains(currentDomains)
             self.coordinates[smallest].setDomain([currentAssignment,])
             if (self.solveWithLCV()):
                 return True
         else:
             return False