Class LinearInt

  • All Implemented Interfaces:
    SatisfiedPresent, StoreAware
    Direct Known Subclasses:
    LinearIntDom

    public class LinearInt
    extends PrimitiveConstraint
    LinearInt constraint implements the weighted summation over several variables .

    sum(i in 1..N)(ai*xi) = b

    It provides the weighted sum from all variables on the list. The weights are integers.

    This implementaiton is based on "Bounds Consistency Techniques for Long Linear Constraints" by Warwick Harvey and Joachim Schimpf

    Version:
    4.8
    • Field Detail

      • idNumber

        static java.util.concurrent.atomic.AtomicInteger idNumber
      • reified

        boolean reified
      • negRel

        static final byte[] negRel
        Defines negated relations
      • relationType

        public byte relationType
        It specifies what relations is used by this constraint
      • x

        IntVar[] x
        It specifies a list of variables being summed.
      • a

        long[] a
        It specifies a list of weights associated with the variables being summed.
      • b

        long b
        It specifies variable for the overall sum.
      • pos

        int pos
        It specifies the index of the last positive coefficient.
      • l

        int l
        It specifies the number of variables/coefficients.
      • I

        long[] I
        It specifies "variability" of each variable
      • sumMin

        long sumMin
        It specifies sum of lower bounds (min values) and sum of upper bounds (max values)
      • sumMax

        long sumMax
        It specifies sum of lower bounds (min values) and sum of upper bounds (max values)
    • Constructor Detail

      • LinearInt

        protected LinearInt()
      • LinearInt

        @Deprecated
        public LinearInt​(Store store,
                         IntVar[] list,
                         int[] weights,
                         java.lang.String rel,
                         int sum)
        Deprecated.
        LinearInt constraint does not use Store parameter any longer.
        Parameters:
        store - current store
        list - variables which are being multiplied by weights.
        weights - weight for each variable.
        rel - the relation, one of "==", "<", ">", "<=", ">=", "!="
        sum - the sum of weighted variables.
      • LinearInt

        @Deprecated
        public LinearInt​(Store store,
                         java.util.List<? extends IntVar> list,
                         java.util.List<java.lang.Integer> weights,
                         java.lang.String rel,
                         int sum)
        Deprecated.
        LinearInt constraint does not use Store parameter any longer.
        It constructs the constraint LinearInt.
        Parameters:
        store - current store
        list - list which are being multiplied by weights.
        weights - weight for each variable.
        rel - the relation, one of "==", "<", ">", "<=", ">=", "!="
        sum - the sum of weighted list.
      • LinearInt

        @Deprecated
        public LinearInt​(Store store,
                         IntVar[] list,
                         int[] weights,
                         java.lang.String rel,
                         IntVar sum)
        Deprecated.
        LinearInt constraint does not use Store parameter any longer.
        Parameters:
        store - current store
        list - variables which are being multiplied by weights.
        weights - weight for each variable.
        rel - the relation, one of "==", "<", ">", "<=", ">=", "!="
        sum - the sum of weighted variables.
      • LinearInt

        public LinearInt​(IntVar[] list,
                         int[] weights,
                         java.lang.String rel,
                         int sum)
        Parameters:
        list - variables which are being multiplied by weights.
        weights - weight for each variable.
        rel - the relation, one of "==", "<", ">", "<=", ">=", "!="
        sum - the sum of weighted variables.
      • LinearInt

        public LinearInt​(java.util.List<? extends IntVar> list,
                         java.util.List<java.lang.Integer> weights,
                         java.lang.String rel,
                         int sum)
        It constructs the constraint LinearInt.
        Parameters:
        list - list which are being multiplied by weights.
        weights - weight for each variable.
        rel - the relation, one of "==", "<", ">", "<=", ">=", "!="
        sum - the sum of weighted list.
      • LinearInt

        public LinearInt​(IntVar[] list,
                         int[] weights,
                         java.lang.String rel,
                         IntVar sum)
        Parameters:
        list - variables which are being multiplied by weights.
        weights - weight for each variable.
        rel - the relation, one of "==", "<", ">", "<=", ">=", "!="
        sum - the sum of weighted variables.
    • Method Detail

      • commonInitialization

        protected void commonInitialization​(Store store,
                                            IntVar[] list,
                                            int[] weights,
                                            java.lang.String rel,
                                            int sum)
      • 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.
      • notConsistency

        public void notConsistency​(Store store)
        Description copied from class: PrimitiveConstraint
        It makes pruning in such a way that constraint is notConsistent. It removes values which always belong to a solution.
        Specified by:
        notConsistency in class PrimitiveConstraint
        Parameters:
        store - the constraint store in which context the notConsistency technique is evaluated.
      • propagate

        public void propagate​(int rel)
      • impose

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

        void computeInit()
      • pruneLtEq

        void pruneLtEq​(long b)
      • pruneGtEq

        void pruneGtEq​(long b)
      • pruneNeq

        void pruneNeq()
      • pruneMin

        private boolean pruneMin​(IntVar x,
                                 long min)
      • pruneMax

        private boolean pruneMax​(IntVar x,
                                 long max)
      • pruneNe

        private boolean pruneNe​(IntVar x,
                                long min,
                                long max,
                                long a)
      • satisfiedEq

        public boolean satisfiedEq()
      • satisfiedNeq

        public boolean satisfiedNeq()
      • satisfiedLtEq

        public boolean satisfiedLtEq​(long b)
      • satisfiedGtEq

        public boolean satisfiedGtEq​(long b)
      • 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.

        Returns:
        true if constraint is possible to verify that it is satisfied.
      • notSatisfied

        public boolean notSatisfied()
        Description copied from class: PrimitiveConstraint
        It checks if constraint would be always not satisfied.
        Specified by:
        notSatisfied in class PrimitiveConstraint
        Returns:
        true if constraint must be notSatisfied, false otherwise.
      • entailed

        private boolean entailed​(int rel)
      • divRoundDown

        private long divRoundDown​(long a,
                                  long b)
      • divRoundUp

        private long divRoundUp​(long a,
                                long b)
      • relation

        public byte relation​(java.lang.String r)
      • rel2String

        public java.lang.String rel2String()
      • checkForOverflow

        void checkForOverflow()
      • 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