Enum FirstSolutionStrategy.Value

java.lang.Object
java.lang.Enum<FirstSolutionStrategy.Value>
com.google.ortools.constraintsolver.FirstSolutionStrategy.Value
All Implemented Interfaces:
com.google.protobuf.Internal.EnumLite, com.google.protobuf.ProtocolMessageEnum, Serializable, Comparable<FirstSolutionStrategy.Value>, java.lang.constant.Constable
Enclosing class:
FirstSolutionStrategy
public static enum FirstSolutionStrategy.Value extends Enum<FirstSolutionStrategy.Value> implements com.google.protobuf.ProtocolMessageEnum
Protobuf enum operations_research.FirstSolutionStrategy.Value

  • Nested Class Summary

    Nested classes/interfaces inherited from class java.lang.Enum

    Enum.EnumDesc<E extends Enum<E>>

  • Enum Constant Summary

    Enum Constants
    Enum Constant
    Description
    ALL_UNPERFORMED
    --- Path insertion heuristics --- Make all nodes inactive.
    AUTOMATIC
    Lets the solver detect which strategy to use according to the model being solved.
    BEST_INSERTION
    Iteratively build a solution by inserting the cheapest node at its cheapest position; the cost of insertion is based on the global cost function of the routing model.
    CHRISTOFIDES
    Christofides algorithm (actually a variant of the Christofides algorithm using a maximal matching instead of a maximum matching, which does not guarantee the 3/2 factor of the approximation on a metric travelling salesman).
    EVALUATOR_STRATEGY
    Same as PATH_CHEAPEST_ARC, except that arc costs are evaluated using the function passed to RoutingModel::SetFirstSolutionEvaluator() (cf. routing.h).
    FIRST_UNBOUND_MIN_VALUE
    Select the first node with an unbound successor and connect it to the first available node.
    GLOBAL_CHEAPEST_ARC
    --- Variable-based heuristics --- Iteratively connect two nodes which produce the cheapest route segment.
    LOCAL_CHEAPEST_ARC
    Select the first node with an unbound successor and connect it to the node which produces the cheapest route segment.
    LOCAL_CHEAPEST_COST_INSERTION
    Same as LOCAL_CHEAPEST_INSERTION except that the cost of insertion is based on the routing model cost function instead of arc costs only.
    LOCAL_CHEAPEST_INSERTION
    Iteratively build a solution by inserting each node at its cheapest position; the cost of insertion is based on the arc cost function.
    PARALLEL_CHEAPEST_INSERTION
    Iteratively build a solution by inserting the cheapest node at its cheapest position; the cost of insertion is based on the arc cost function.
    PARALLEL_SAVINGS
    Parallel version of the Savings algorithm.
    PATH_CHEAPEST_ARC
    --- Path addition heuristics --- Starting from a route "start" node, connect it to the node which produces the cheapest route segment, then extend the route by iterating on the last node added to the route.
    PATH_MOST_CONSTRAINED_ARC
    Same as PATH_CHEAPEST_ARC, but arcs are evaluated with a comparison-based selector which will favor the most constrained arc first.
    SAVINGS
    Savings algorithm (Clarke & Wright).
    SEQUENTIAL_CHEAPEST_INSERTION
    Iteratively build a solution by constructing routes sequentially, for each route inserting the cheapest node at its cheapest position until the route is completed; the cost of insertion is based on the arc cost function.
    SWEEP
    Sweep algorithm (Wren & Holliday).
    UNRECOGNIZED
     
    UNSET
    See the homonymous value in LocalSearchMetaheuristic.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    ALL_UNPERFORMED_VALUE
    --- Path insertion heuristics --- Make all nodes inactive.
    static final int
    AUTOMATIC_VALUE
    Lets the solver detect which strategy to use according to the model being solved.
    static final int
    BEST_INSERTION_VALUE
    Iteratively build a solution by inserting the cheapest node at its cheapest position; the cost of insertion is based on the global cost function of the routing model.
    static final int
    CHRISTOFIDES_VALUE
    Christofides algorithm (actually a variant of the Christofides algorithm using a maximal matching instead of a maximum matching, which does not guarantee the 3/2 factor of the approximation on a metric travelling salesman).
    static final int
    EVALUATOR_STRATEGY_VALUE
    Same as PATH_CHEAPEST_ARC, except that arc costs are evaluated using the function passed to RoutingModel::SetFirstSolutionEvaluator() (cf. routing.h).
    static final int
    FIRST_UNBOUND_MIN_VALUE_VALUE
    Select the first node with an unbound successor and connect it to the first available node.
    static final int
    GLOBAL_CHEAPEST_ARC_VALUE
    --- Variable-based heuristics --- Iteratively connect two nodes which produce the cheapest route segment.
    static final int
    LOCAL_CHEAPEST_ARC_VALUE
    Select the first node with an unbound successor and connect it to the node which produces the cheapest route segment.
    static final int
    LOCAL_CHEAPEST_COST_INSERTION_VALUE
    Same as LOCAL_CHEAPEST_INSERTION except that the cost of insertion is based on the routing model cost function instead of arc costs only.
    static final int
    LOCAL_CHEAPEST_INSERTION_VALUE
    Iteratively build a solution by inserting each node at its cheapest position; the cost of insertion is based on the arc cost function.
    static final int
    PARALLEL_CHEAPEST_INSERTION_VALUE
    Iteratively build a solution by inserting the cheapest node at its cheapest position; the cost of insertion is based on the arc cost function.
    static final int
    PARALLEL_SAVINGS_VALUE
    Parallel version of the Savings algorithm.
    static final int
    PATH_CHEAPEST_ARC_VALUE
    --- Path addition heuristics --- Starting from a route "start" node, connect it to the node which produces the cheapest route segment, then extend the route by iterating on the last node added to the route.
    static final int
    PATH_MOST_CONSTRAINED_ARC_VALUE
    Same as PATH_CHEAPEST_ARC, but arcs are evaluated with a comparison-based selector which will favor the most constrained arc first.
    static final int
    SAVINGS_VALUE
    Savings algorithm (Clarke & Wright).
    static final int
    SEQUENTIAL_CHEAPEST_INSERTION_VALUE
    Iteratively build a solution by constructing routes sequentially, for each route inserting the cheapest node at its cheapest position until the route is completed; the cost of insertion is based on the arc cost function.
    static final int
    SWEEP_VALUE
    Sweep algorithm (Wren & Holliday).
    static final int
    UNSET_VALUE
    See the homonymous value in LocalSearchMetaheuristic.

  • Method Summary

    Modifier and Type
    Method
    Description
    static FirstSolutionStrategy.Value
    forNumber(int value)
     
    static com.google.protobuf.Descriptors.EnumDescriptor
    getDescriptor()
     
    final com.google.protobuf.Descriptors.EnumDescriptor
    getDescriptorForType()
     
    final int
    getNumber()
     
    final com.google.protobuf.Descriptors.EnumValueDescriptor
    getValueDescriptor()
     
    static com.google.protobuf.Internal.EnumLiteMap<FirstSolutionStrategy.Value>
    internalGetValueMap()
     
    static FirstSolutionStrategy.Value
    valueOf(int value)
    Deprecated.
    static FirstSolutionStrategy.Value
    valueOf(com.google.protobuf.Descriptors.EnumValueDescriptor desc)
    Returns the enum constant of this type with the specified name.
    static FirstSolutionStrategy.Value
    valueOf(String name)
    Returns the enum constant of this type with the specified name.
    static FirstSolutionStrategy.Value[]
    values()
    Returns an array containing the constants of this enum type, in the order they are declared.

    Methods inherited from class java.lang.Enum

    clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

    Methods inherited from class java.lang.Object

    getClass, notify, notifyAll, wait, wait, wait

  • Enum Constant Details

    • UNSET

      public static final FirstSolutionStrategy.Value UNSET
       See the homonymous value in LocalSearchMetaheuristic.
      UNSET = 0;

    • AUTOMATIC

      public static final FirstSolutionStrategy.Value AUTOMATIC
       Lets the solver detect which strategy to use according to the model being
 solved.
      AUTOMATIC = 15;

    • PATH_CHEAPEST_ARC

      public static final FirstSolutionStrategy.Value PATH_CHEAPEST_ARC
       --- Path addition heuristics ---
 Starting from a route "start" node, connect it to the node which produces
 the cheapest route segment, then extend the route by iterating on the
 last node added to the route.
      PATH_CHEAPEST_ARC = 3;

    • PATH_MOST_CONSTRAINED_ARC

      public static final FirstSolutionStrategy.Value PATH_MOST_CONSTRAINED_ARC
       Same as PATH_CHEAPEST_ARC, but arcs are evaluated with a comparison-based
 selector which will favor the most constrained arc first. To assign a
 selector to the routing model, see
 RoutingModel::ArcIsMoreConstrainedThanArc() in routing.h for details.
      PATH_MOST_CONSTRAINED_ARC = 4;

    • EVALUATOR_STRATEGY

      public static final FirstSolutionStrategy.Value EVALUATOR_STRATEGY
       Same as PATH_CHEAPEST_ARC, except that arc costs are evaluated using the
 function passed to RoutingModel::SetFirstSolutionEvaluator()
 (cf. routing.h).
      EVALUATOR_STRATEGY = 5;

    • SAVINGS

      public static final FirstSolutionStrategy.Value SAVINGS
       Savings algorithm (Clarke & Wright).
 Reference: Clarke, G. & Wright, J.W.:
 "Scheduling of Vehicles from a Central Depot to a Number of Delivery
 Points", Operations Research, Vol. 12, 1964, pp. 568-581
      SAVINGS = 10;

    • PARALLEL_SAVINGS

      public static final FirstSolutionStrategy.Value PARALLEL_SAVINGS
       Parallel version of the Savings algorithm.
 Instead of extending a single route until it is no longer possible,
 the parallel version iteratively considers the next most improving
 feasible saving and possibly builds several routes in parallel.
      PARALLEL_SAVINGS = 17;

    • SWEEP

      public static final FirstSolutionStrategy.Value SWEEP
       Sweep algorithm (Wren & Holliday).
 Reference: Anthony Wren & Alan Holliday: Computer Scheduling of Vehicles
 from One or More Depots to a Number of Delivery Points Operational
 Research Quarterly (1970-1977),
 Vol. 23, No. 3 (Sep., 1972), pp. 333-344
      SWEEP = 11;

    • CHRISTOFIDES

      public static final FirstSolutionStrategy.Value CHRISTOFIDES
       Christofides algorithm (actually a variant of the Christofides algorithm
 using a maximal matching instead of a maximum matching, which does
 not guarantee the 3/2 factor of the approximation on a metric travelling
 salesman). Works on generic vehicle routing models by extending a route
 until no nodes can be inserted on it.
 Reference: Nicos Christofides, Worst-case analysis of a new heuristic for
 the travelling salesman problem, Report 388, Graduate School of
 Industrial Administration, CMU, 1976.
      CHRISTOFIDES = 13;

    • ALL_UNPERFORMED

      public static final FirstSolutionStrategy.Value ALL_UNPERFORMED
       --- Path insertion heuristics ---
 Make all nodes inactive. Only finds a solution if nodes are optional (are
 element of a disjunction constraint with a finite penalty cost).
      ALL_UNPERFORMED = 6;

    • BEST_INSERTION

      public static final FirstSolutionStrategy.Value BEST_INSERTION
       Iteratively build a solution by inserting the cheapest node at its
 cheapest position; the cost of insertion is based on the global cost
 function of the routing model. As of 2/2012, only works on models with
 optional nodes (with finite penalty costs).
      BEST_INSERTION = 7;

    • PARALLEL_CHEAPEST_INSERTION

      public static final FirstSolutionStrategy.Value PARALLEL_CHEAPEST_INSERTION
       Iteratively build a solution by inserting the cheapest node at its
 cheapest position; the cost of insertion is based on the arc cost
 function. Is faster than BEST_INSERTION.
      PARALLEL_CHEAPEST_INSERTION = 8;

    • SEQUENTIAL_CHEAPEST_INSERTION

      public static final FirstSolutionStrategy.Value SEQUENTIAL_CHEAPEST_INSERTION
       Iteratively build a solution by constructing routes sequentially, for
 each route inserting the cheapest node at its cheapest position until the
 route is completed; the cost of insertion is based on the arc cost
 function. Is faster than PARALLEL_CHEAPEST_INSERTION.
      SEQUENTIAL_CHEAPEST_INSERTION = 14;

    • LOCAL_CHEAPEST_INSERTION

      public static final FirstSolutionStrategy.Value LOCAL_CHEAPEST_INSERTION
       Iteratively build a solution by inserting each node at its cheapest
 position; the cost of insertion is based on the arc cost function.
 Differs from PARALLEL_CHEAPEST_INSERTION by the node selected for
 insertion; here nodes are considered in decreasing order of distance to
 the start/ends of the routes, i.e. farthest nodes are inserted first.
 Is faster than SEQUENTIAL_CHEAPEST_INSERTION.
      LOCAL_CHEAPEST_INSERTION = 9;

    • LOCAL_CHEAPEST_COST_INSERTION

      public static final FirstSolutionStrategy.Value LOCAL_CHEAPEST_COST_INSERTION
       Same as LOCAL_CHEAPEST_INSERTION except that the cost of insertion is
 based on the routing model cost function instead of arc costs only.
      LOCAL_CHEAPEST_COST_INSERTION = 16;

    • GLOBAL_CHEAPEST_ARC

      public static final FirstSolutionStrategy.Value GLOBAL_CHEAPEST_ARC
       --- Variable-based heuristics ---
 Iteratively connect two nodes which produce the cheapest route segment.
      GLOBAL_CHEAPEST_ARC = 1;

    • LOCAL_CHEAPEST_ARC

      public static final FirstSolutionStrategy.Value LOCAL_CHEAPEST_ARC
       Select the first node with an unbound successor and connect it to the
 node which produces the cheapest route segment.
      LOCAL_CHEAPEST_ARC = 2;

    • FIRST_UNBOUND_MIN_VALUE

      public static final FirstSolutionStrategy.Value FIRST_UNBOUND_MIN_VALUE
       Select the first node with an unbound successor and connect it to the
 first available node.
 This is equivalent to the CHOOSE_FIRST_UNBOUND strategy combined with
 ASSIGN_MIN_VALUE (cf. constraint_solver.h).
      FIRST_UNBOUND_MIN_VALUE = 12;

    • UNRECOGNIZED

      public static final FirstSolutionStrategy.Value UNRECOGNIZED

  • Field Details

    • UNSET_VALUE

      public static final int UNSET_VALUE
       See the homonymous value in LocalSearchMetaheuristic.
      UNSET = 0;
      See Also:

    • AUTOMATIC_VALUE

      public static final int AUTOMATIC_VALUE
       Lets the solver detect which strategy to use according to the model being
 solved.
      AUTOMATIC = 15;
      See Also:

    • PATH_CHEAPEST_ARC_VALUE

      public static final int PATH_CHEAPEST_ARC_VALUE
       --- Path addition heuristics ---
 Starting from a route "start" node, connect it to the node which produces
 the cheapest route segment, then extend the route by iterating on the
 last node added to the route.
      PATH_CHEAPEST_ARC = 3;
      See Also:

    • PATH_MOST_CONSTRAINED_ARC_VALUE

      public static final int PATH_MOST_CONSTRAINED_ARC_VALUE
       Same as PATH_CHEAPEST_ARC, but arcs are evaluated with a comparison-based
 selector which will favor the most constrained arc first. To assign a
 selector to the routing model, see
 RoutingModel::ArcIsMoreConstrainedThanArc() in routing.h for details.
      PATH_MOST_CONSTRAINED_ARC = 4;
      See Also:

    • EVALUATOR_STRATEGY_VALUE

      public static final int EVALUATOR_STRATEGY_VALUE
       Same as PATH_CHEAPEST_ARC, except that arc costs are evaluated using the
 function passed to RoutingModel::SetFirstSolutionEvaluator()
 (cf. routing.h).
      EVALUATOR_STRATEGY = 5;
      See Also:

    • SAVINGS_VALUE

      public static final int SAVINGS_VALUE
       Savings algorithm (Clarke & Wright).
 Reference: Clarke, G. & Wright, J.W.:
 "Scheduling of Vehicles from a Central Depot to a Number of Delivery
 Points", Operations Research, Vol. 12, 1964, pp. 568-581
      SAVINGS = 10;
      See Also:

    • PARALLEL_SAVINGS_VALUE

      public static final int PARALLEL_SAVINGS_VALUE
       Parallel version of the Savings algorithm.
 Instead of extending a single route until it is no longer possible,
 the parallel version iteratively considers the next most improving
 feasible saving and possibly builds several routes in parallel.
      PARALLEL_SAVINGS = 17;
      See Also:

    • SWEEP_VALUE

      public static final int SWEEP_VALUE
       Sweep algorithm (Wren & Holliday).
 Reference: Anthony Wren & Alan Holliday: Computer Scheduling of Vehicles
 from One or More Depots to a Number of Delivery Points Operational
 Research Quarterly (1970-1977),
 Vol. 23, No. 3 (Sep., 1972), pp. 333-344
      SWEEP = 11;
      See Also:

    • CHRISTOFIDES_VALUE

      public static final int CHRISTOFIDES_VALUE
       Christofides algorithm (actually a variant of the Christofides algorithm
 using a maximal matching instead of a maximum matching, which does
 not guarantee the 3/2 factor of the approximation on a metric travelling
 salesman). Works on generic vehicle routing models by extending a route
 until no nodes can be inserted on it.
 Reference: Nicos Christofides, Worst-case analysis of a new heuristic for
 the travelling salesman problem, Report 388, Graduate School of
 Industrial Administration, CMU, 1976.
      CHRISTOFIDES = 13;
      See Also:

    • ALL_UNPERFORMED_VALUE

      public static final int ALL_UNPERFORMED_VALUE
       --- Path insertion heuristics ---
 Make all nodes inactive. Only finds a solution if nodes are optional (are
 element of a disjunction constraint with a finite penalty cost).
      ALL_UNPERFORMED = 6;
      See Also:

    • BEST_INSERTION_VALUE

      public static final int BEST_INSERTION_VALUE
       Iteratively build a solution by inserting the cheapest node at its
 cheapest position; the cost of insertion is based on the global cost
 function of the routing model. As of 2/2012, only works on models with
 optional nodes (with finite penalty costs).
      BEST_INSERTION = 7;
      See Also:

    • PARALLEL_CHEAPEST_INSERTION_VALUE

      public static final int PARALLEL_CHEAPEST_INSERTION_VALUE
       Iteratively build a solution by inserting the cheapest node at its
 cheapest position; the cost of insertion is based on the arc cost
 function. Is faster than BEST_INSERTION.
      PARALLEL_CHEAPEST_INSERTION = 8;
      See Also:

    • SEQUENTIAL_CHEAPEST_INSERTION_VALUE

      public static final int SEQUENTIAL_CHEAPEST_INSERTION_VALUE
       Iteratively build a solution by constructing routes sequentially, for
 each route inserting the cheapest node at its cheapest position until the
 route is completed; the cost of insertion is based on the arc cost
 function. Is faster than PARALLEL_CHEAPEST_INSERTION.
      SEQUENTIAL_CHEAPEST_INSERTION = 14;
      See Also:

    • LOCAL_CHEAPEST_INSERTION_VALUE

      public static final int LOCAL_CHEAPEST_INSERTION_VALUE
       Iteratively build a solution by inserting each node at its cheapest
 position; the cost of insertion is based on the arc cost function.
 Differs from PARALLEL_CHEAPEST_INSERTION by the node selected for
 insertion; here nodes are considered in decreasing order of distance to
 the start/ends of the routes, i.e. farthest nodes are inserted first.
 Is faster than SEQUENTIAL_CHEAPEST_INSERTION.
      LOCAL_CHEAPEST_INSERTION = 9;
      See Also:

    • LOCAL_CHEAPEST_COST_INSERTION_VALUE

      public static final int LOCAL_CHEAPEST_COST_INSERTION_VALUE
       Same as LOCAL_CHEAPEST_INSERTION except that the cost of insertion is
 based on the routing model cost function instead of arc costs only.
      LOCAL_CHEAPEST_COST_INSERTION = 16;
      See Also:

    • GLOBAL_CHEAPEST_ARC_VALUE

      public static final int GLOBAL_CHEAPEST_ARC_VALUE
       --- Variable-based heuristics ---
 Iteratively connect two nodes which produce the cheapest route segment.
      GLOBAL_CHEAPEST_ARC = 1;
      See Also:

    • LOCAL_CHEAPEST_ARC_VALUE

      public static final int LOCAL_CHEAPEST_ARC_VALUE
       Select the first node with an unbound successor and connect it to the
 node which produces the cheapest route segment.
      LOCAL_CHEAPEST_ARC = 2;
      See Also:

    • FIRST_UNBOUND_MIN_VALUE_VALUE

      public static final int FIRST_UNBOUND_MIN_VALUE_VALUE
       Select the first node with an unbound successor and connect it to the
 first available node.
 This is equivalent to the CHOOSE_FIRST_UNBOUND strategy combined with
 ASSIGN_MIN_VALUE (cf. constraint_solver.h).
      FIRST_UNBOUND_MIN_VALUE = 12;
      See Also:

  • Method Details

    • values

      public static FirstSolutionStrategy.Value[] values()
      Returns an array containing the constants of this enum type, in the order they are declared.
      Returns:
      an array containing the constants of this enum type, in the order they are declared

    • valueOf

      public static FirstSolutionStrategy.Value valueOf(String name)
      Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
      Parameters:
      name - the name of the enum constant to be returned.
      Returns:
      the enum constant with the specified name
      Throws:
      IllegalArgumentException - if this enum type has no constant with the specified name
      NullPointerException - if the argument is null

    • getNumber

      public final int getNumber()
      Specified by:
      getNumber in interface com.google.protobuf.Internal.EnumLite
      Specified by:
      getNumber in interface com.google.protobuf.ProtocolMessageEnum

    • valueOf

      @Deprecated public static FirstSolutionStrategy.Value valueOf(int value)
      Deprecated.
      Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
      Parameters:
      value - the name of the enum constant to be returned.
      Returns:
      the enum constant with the specified name
      Throws:
      IllegalArgumentException - if this enum type has no constant with the specified name
      NullPointerException - if the argument is null

    • forNumber

      public static FirstSolutionStrategy.Value forNumber(int value)
      Parameters:
      value - The numeric wire value of the corresponding enum entry.
      Returns:
      The enum associated with the given numeric wire value.

    • internalGetValueMap

      public static com.google.protobuf.Internal.EnumLiteMap<FirstSolutionStrategy.Value> internalGetValueMap()

    • getValueDescriptor

      public final com.google.protobuf.Descriptors.EnumValueDescriptor getValueDescriptor()
      Specified by:
      getValueDescriptor in interface com.google.protobuf.ProtocolMessageEnum

    • getDescriptorForType

      public final com.google.protobuf.Descriptors.EnumDescriptor getDescriptorForType()
      Specified by:
      getDescriptorForType in interface com.google.protobuf.ProtocolMessageEnum

    • getDescriptor

      public static com.google.protobuf.Descriptors.EnumDescriptor getDescriptor()

    • valueOf

      public static FirstSolutionStrategy.Value valueOf(com.google.protobuf.Descriptors.EnumValueDescriptor desc)
      Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
      Parameters:
      desc - the name of the enum constant to be returned.
      Returns:
      the enum constant with the specified name
      Throws:
      IllegalArgumentException - if this enum type has no constant with the specified name
      NullPointerException - if the argument is null