Class Count

  • All Implemented Interfaces:
    SatisfiedPresent

    public class Count
    extends Constraint
    implements SatisfiedPresent
    Count constraint implements the counting over number of occurrences of a given value in a list of variables. The number of occurrences is specified by variable idNumber.
    Version:
    4.7
    • Field Detail

      • idNumber

        static final java.util.concurrent.atomic.AtomicInteger idNumber
      • counter

        public final IntVar counter
        It specifies variable idNumber to count the number of occurences of the specified value in a list.
      • list

        public final IntVar[] list
        The list of variables which are checked and counted if equal to specified value.
      • value

        public final int value
        The value to which is any variable is equal to makes the constraint count it.
      • position

        private TimeStamp<java.lang.Integer> position
      • equal

        private TimeStamp<java.lang.Integer> equal
    • Constructor Detail

      • Count

        public Count​(IntVar[] list,
                     IntVar counter,
                     int value)
        It constructs a Count constraint.
        Parameters:
        value - value which is counted
        list - variables which equality to val is counted.
        counter - number of variables equal to val.
      • Count

        public Count​(java.util.List<? extends IntVar> list,
                     IntVar counter,
                     int value)
        It constructs a Count constraint.
        Parameters:
        value - value which is counted
        list - variables which equality to val is counted.
        counter - number of variables equal to val.
    • Method Detail

      • 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.
      • 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.
      • swap

        private void swap​(int i,
                          int j)
      • satisfied

        public boolean satisfied()
        Description copied from interface: SatisfiedPresent
        It checks if the constraint is satisfied. It can return false even if constraint is satisfied but not all variables in its scope are grounded. It needs to return true if all variables in its scope are grounded and constraint is satisfied.

        Implementations of this interface for constraints that are not PrimitiveConstraint may require constraint imposition and consistency check as a requirement to work correctly.

        Specified by:
        satisfied in interface SatisfiedPresent
        Returns:
        true if constraint is possible to verify that it is satisfied.
      • toString

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