Class ExtensionalConflictVA

All Implemented Interfaces:
Stateful, UsesQueueVariable

public class ExtensionalConflictVA extends Constraint implements UsesQueueVariable, Stateful
Extensional constraint assures that none of the tuples explicitly given is enforced in the relation.

This implementation tries to balance the usage of memory versus time efficiency.

Version:
4.10
  • Field Details

    • debugAll

      static final boolean debugAll
      See Also:
    • debugPruning

      static final boolean debugPruning
      See Also:
    • idNumber

      static AtomicInteger idNumber
    • numberTuples

      int numberTuples
    • store

      Store store
    • tuples

      int[][][][] tuples
      It represents tuples which are supports for each of the variables. The first index denotes variable index. The second index denotes value index. The third index denotes tuple.
    • tuplesFromConstructor

      public int[][] tuplesFromConstructor
      It specifies the tuples given in the constructor.
    • values

      int[][] values
      It represents values which are supported for a variable.
    • variableQueue

      LinkedHashSet<Var> variableQueue
    • list

      public IntVar[] list
      It stores variables within this extensional constraint, order does matter.
    • satisfiedAlreadyAtImposition

      private boolean satisfiedAlreadyAtImposition
    • tuple

      int[] tuple
    • lastofsequence

      int[][][] lastofsequence
    • supports

      int[][][] supports
  • Constructor Details

    • ExtensionalConflictVA

      @Deprecated public ExtensionalConflictVA(IntVar[] list)
      Deprecated.
      Partial constructor which stores variables involved in a constraint but does not get information about tuples yet. The tuples must set separately.
      Parameters:
      list - list of variables for constraint
    • ExtensionalConflictVA

      public ExtensionalConflictVA(IntVar[] list, int[][] tuples)
      Constructor stores reference to tuples until imposition, any changes to tuples parameter will be reflected in the constraint behavior. Changes to tuples should not performed under any circumstances. The tuples array is not copied to save memory and time.
      Parameters:
      list - list of variables for the conflict constraint
      tuples - list of forbidden tuples
    • ExtensionalConflictVA

      public ExtensionalConflictVA(List<? extends IntVar> variables, int[][] tuples)
      The constructor does not create local copy of tuples array. Any changes to this array will reflect on constraint behavior. Most probably incorrect as other data structures will not change accordingly.
      Parameters:
      variables - the scope of the extensional conflict constraint.
      tuples - the conflict (forbidden) tuples for that constraint.
  • Method Details

    • seekSupportVA

      public int[] seekSupportVA(int varPosition, int value)
      It seeks support tuple for a given variable and its value.
      Parameters:
      varPosition - variable for which the support is seeked.
      value - value of the variable for which support is seeked.
      Returns:
      support tuple supporting varPosition-value pair.
    • recordSupport

      private void recordSupport(int varPosition, int value, int[] t)
    • setFirstValid

      public int[] setFirstValid(int varPosition, int value)
      It computes the first valid tuple given restriction that a variable will be equal to a given value.
      Parameters:
      varPosition - the position of the variable.
      value - the value of the variable.
      Returns:
      the smallest valid tuple supporting varPosition-value pair.
    • isDisallowed

      public int isDisallowed(int varPosition, int value, int[] t)
      It returns the position of disallowed tuple in the array of tuples for a given variable-value pair.
      Parameters:
      varPosition - variable for which we search for the forbidden tuple.
      value - value for which we search for the forbidden tuple.
      t - tuple which we check for forbidness.
      Returns:
      position of the forbidden tuple, -1 if it is not forbidden.
    • seekInvalidPosition

      public int seekInvalidPosition(int[] t)
      It finds the position at which the tuple is invalid. The value is not in the domain of the corresponding variable.
      Parameters:
      t - tuple being check for in-validity
      Returns:
      the position in the tuple at which the corresponding variable does not contain the value used by tuple, -1 if no invalid position exists.
    • removeLevel

      public void removeLevel(int level)
      It puts back tuples which have lost their support status at the level which is being removed.
      Specified by:
      removeLevel in interface Stateful
      Parameters:
      level - the level which is being removed.
    • consistency

      public void consistency(Store store)
      Description copied from class: Constraint
      It is a (most probably incomplete) consistency function which removes the values from variables domains. Only values which do not have any support in a solution space are removed.
      Specified by:
      consistency in class Constraint
      Parameters:
      store - constraint store within which the constraint consistency is being checked.
    • findPosition

      protected int findPosition(int value, int[] values)
    • getDefaultConsistencyPruningEvent

      public int getDefaultConsistencyPruningEvent()
      Specified by:
      getDefaultConsistencyPruningEvent in class Constraint
    • impose

      public void impose(Store store)
      Description copied from class: Constraint
      It imposes the constraint in a given store.
      Overrides:
      impose in class Constraint
      Parameters:
      store - the constraint store to which the constraint is imposed to.
    • computeLastOfSequence

      private int computeLastOfSequence(int[][] is, int posVar, int l)
    • queueVariable

      public void queueVariable(int level, Var var)
      Description copied from class: Constraint
      This is a function called to indicate which variable in a scope of constraint has changed. It also indicates a store level at which the change has occurred.
      Overrides:
      queueVariable in class Constraint
      Parameters:
      level - the level of the store at which the change has occurred.
      var - variable which has changed.
    • smaller

      boolean smaller(int[] tuple1, int[] tuple2)
    • equal

      boolean equal(int[] tuple1, int[] tuple2)
    • toString

      public String toString()
      Description copied from class: Constraint
      It produces a string representation of a constraint state.
      Overrides:
      toString in class Constraint